https://wiki.math.wisc.edu/api.php?action=feedcontributions&user=Apisa&feedformat=atomUW-Math Wiki - User contributions [en]2024-03-29T00:13:13ZUser contributionsMediaWiki 1.39.5https://wiki.math.wisc.edu/index.php?title=Group_Actions_and_Dynamics_Seminar&diff=26255Group Actions and Dynamics Seminar2024-03-04T03:26:47Z<p>Apisa: /* Spring Abstracts */</p>
<hr />
<div>During the Spring 2024 semester, '''RTG / Group Actions and Dynamics''' seminar meets in room '''Sterling Hall 3425''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
== Spring 2024 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 22<br />
|[https://sites.google.com/view/aaron-messerla/ Aaron Messerla] (UIC)<br />
|Quasi-isometries of relatively hyperbolic groups with an elementary hierarchy<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|January 24 (1pm in VV 901)<br />
|[https://mitul-islam.github.io/ Mitul Islam] (Max-Planck-Institut)<br />
|Morse-ness in convex projective geometry<br />
|Zimmer<br />
|<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|Rational surface groups on the Hitchin component<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|Bootstrapping dynamics in the moduli space of non-orientable surfaces<br />
|Uyanik<br />
|<br />
|-<br />
|February 12<br />
|[https://www.noellesawyer.com Noelle Sawyer] (Southwestern)<br />
|Unique Equilibrium States for Geodesic Flows<br />
|Loving, Uyanik, Work<br />
|<br />
|-<br />
|February 19<br />
|[https://web.math.utk.edu/~yqing/ Yulan Qing] (Tennessee)<br />
|Geometric Boundary of Groups<br />
|Zimmer<br />
|<br />
|-<br />
|February 26<br />
|Blandine Galiay (IHES)<br />
|Divisible convex sets in flag manifolds and rigidity<br />
|Zimmer<br />
|<br />
|-<br />
|March 4<br />
|[http://userhome.brooklyn.cuny.edu/aulicino/ David Aulicino] (Brooklyn College)<br />
|Siegel-Veech Constants of Cyclic Covers of Generic Translation Surfaces<br />
|Apisa<br />
|<br />
|-<br />
|March 11<br />
|[https://aacalderon.com/ Aaron Calderon] (Chicago)<br />
|TBA<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|March 18<br />
|[http://sub.mersion.cc Josh Southerland] (Indiana)<br />
|TBA<br />
|Fisher<br />
|<br />
|-<br />
|April 1<br />
|[http://www.caglaruyanik.com Caglar Uyanik] (UW)<br />
|TBA<br />
|local<br />
|<br />
|-<br />
|April 8<br />
|[https://mabainbr.pages.iu.edu/?_gl=1*r2jhoy*_ga*OTk3MTk0Mzg3LjE3MDQ5OTU1MTA.*_ga_61CH0D2DQW*MTcwNDk5NTYyMy4xLjAuMTcwNDk5NTYyMy42MC4wLjA.&_ga=2.157330302.532468181.1704995624-997194387.1704995510 Matt Bainbridge] (Indiana)<br />
|TBA<br />
|Apisa<br />
|<br />
|-<br />
|April 15<br />
|[https://math.hunter.cuny.edu/ilyakapo/ Ilya Kapovich] (CUNY)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 22<br />
|[https://sites.google.com/view/yuchanchang/ Yu-Chan Chang] (Wesleyan)<br />
|TBA<br />
|Dymarz<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Kent, Loving, Uyanik<br />
|}<br />
<br />
== Spring Abstracts ==<br />
===Aaron Messerla===<br />
<br />
Sela introduced limit groups in his work on the Tarski problem, and showed that each limit group has a cyclic hierarchy. We prove that a class of relatively hyperbolic groups, equipped with a hierarchy similar to the one for limit groups, is closed under quasi-isometry. Additionally, these groups share some of the algebraic properties of limit groups. In this talk I plan to present motivation for and introduce the class of groups studied, as well as present some of the results for this class.<br />
===Mitul Islam===<br />
<br />
The (Hilbert metric) geometry of properly convex domains generalizes real hyperbolic geometry. This generalization is far from the Riemannian notion of non-positive curvature, but they have some intriguing similarities. I will explore this connection from a coarse geometry viewpoint.<br />
The focus will be on Morse geodesics ("negatively curved directions", in a coarse sense) in properly convex domains. I will show that Morse-ness can be characterized entirely using linear algebraic data (i.e. singular values of matrices that track the geodesic). Further, I will discuss how this coarse geometric notion of Morse is related to the symmetric space geometry as well as the smoothness of boundary points. This is joint work with Theodore Weisman.<br />
<br />
===Michael Zshornack===<br />
<br />
Margulis's work on lattices in higher-rank and a number of questions on the existence of surface subgroups motivate the need for understanding arithmetic properties of spaces of surface group representations. In recent work with Jacques Audibert, we outline one possible approach towards understanding such properties for the Hitchin component, one particularly nice space of representations. We utilize the underlying geometry of this space to reduce questions about its arithmetic to questions about the arithmetic of certain algebraic groups, which in turn, allows us to characterize the rational points on these components. In this talk, I'll give an overview of the geometric methods behind the proof of our result and indicate some natural questions about the nature of the resulting surface group actions that follow.<br />
<br />
===Sayantan Khan===<br />
<br />
The moduli spaces of non-orientable hyperbolic surfaces behave significantly differently from their orientable counterparts.<br />
They have infinite volume, almost all geodesic flow orbits escape off to infinity, and the growth of mapping class group orbit points and simple closed curves is believed to have non-integer exponents, unlike in the orientable setting.<br />
In this talk, we outline some of the oddities of these moduli spaces, and outline an approach for studying the dynamics on these spaces via Patterson-Sullivan theory.<br />
A key obstruction to imitating the techniques from the orientable setting is that a number of these techniques rely on the dynamics of the geodesic flow and the mapping class group action on Teichmüller spaces of orientable surfaces, which is not something we can do in the non-orientable setting, since that is what we are trying to prove.<br />
The way around these obstructions is by proving weaker versions of these dynamical statements using a dynamics free approach, which we then use to bootstrap the stronger results.<br />
<br />
===Noelle Sawyer===<br />
<br />
In this talk I will discuss some known results about the geodesics and equilibrium states of the geodesic flow in negative curvature. After, I will introduce some of the tools and techniques needed to show the uniqueness of equilibrium states in the setting of translation surfaces. If time allows, I will talk about some of our upcoming work about the Bernoulli property. This is joint work with Benjamin Call, Dave Constantine, Alena Erchenko, and Grace Work. <br />
<br />
<br />
<br />
===Yulan Qing===<br />
<br />
Gromov boundary provides a useful compactification for all infinite-diameter Gromov hyperbolic spaces. It consists of all geodesic rays starting at a given base-point and it is an essential tool in the study of the coarse geometry of hyperbolic groups. In this talk we generalize the Gromov boundary. We first construct the sublinearly Morse boundaries and show that it is a QI-invariant, metrizable topological space. We show sublinearly Morse directions are generic both in the sense of Patterson-Sullivan and in the sense of random walk. <br />
<br />
The sublinearly Morse boundaries are subsets of all directions with desired properties. In the second half of the talk, we will truly consider the space of all directions and show that with some minimal assumptions on the space, the resulting boundary is a QI-invariant topology space in which many existing boundaries are embedded. This talk is based on a series of work with Kasra Rafi and Giulio Tiozzo.<br />
<br />
===Blandine Galiay===<br />
<br />
Divisible convex sets have been widely studied since the 1960s. They are proper domains of the projective space that admit a cocompact action of a discrete subgroup of the linear projective group. The best-known examples are symmetric spaces embedded in the projective space, but there are also many nonsymmetric examples. It is natural to seek to generalize this theory, by replacing the projective space by a flag variety G/P, where G is a real semisimple non-compact Lie group and P a parabolic of G. A question of van Limbeek and Zimmer is then: are there examples of divisible convex sets in G/P that are nonsymmetric? In a number of cases, it has been proved that there are not. In this talk, we will focus on some particular classes of flag varieties in which rigidity can indeed be observed.<br />
<br />
===David Aulicino===<br />
<br />
We consider generic translation surfaces of genus g>0 with marked points and take covers branched over the marked points such that the monodromy of every element in the fundamental group lies in a cyclic group of order d. Given a translation surface, the number of cylinders with waist curve of length at most L grows like L^2. By work of Veech and Eskin-Masur, when normalizing the number of cylinders by L^2, the limit as L goes to infinity exists and the resulting number is called a Siegel-Veech constant. The same holds true if we weight the cylinders by their area. Remarkably, the Siegel-Veech constant resulting from counting cylinders weighted by area is independent of the number of branch points n. All necessary background will be given and a connection to combinatorics will be presented. This is joint work with Aaron Calderon, Carlos Matheus, Nick Salter, and Martin Schmoll.<br />
<br />
===Aaron Calderon===<br />
===Josh Southerland===<br />
===Caglar Uyanik===<br />
===Matt Bainbridge===<br />
===Ilya Kapovich===<br />
===Yu-Chan Chang===<br />
===Chris Leininger===<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|Periodic points of Prym eigenforms<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|Non-planarity of SL(2,Z)-orbits of origamis<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|Colloquium by [https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] at 4pm<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
Origamis (also known as square-tiled surfaces) arise naturally in a variety of settings in low-dimensional topology. They can be thought of as generalisations of the torus (the unit square with opposite sides glued) since they are surfaces obtained by gluing the opposite sides of a collection of unit squares. There is a natural action of the matrix group SL(2,Z) on origamis. In genus two (with some extra conditions) the orbits of this action were classified by Hubert-Lelièvre and McMullen. By considering a generating set of size two for SL(2,Z) and varying the number of squares used to build the origamis, we can turn these orbits into an infinite family of four-valent graphs. It is a long-standing conjecture of McMullen that these orbit graphs form a family of expander graphs. In this talk, giving indirect evidence for this conjecture, I will discuss joint work with Carlos Matheus in which we show that these orbit graphs are eventually non-planar - a requirement of any family of expander graphs.<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Group_Actions_and_Dynamics_Seminar&diff=26254Group Actions and Dynamics Seminar2024-03-04T03:26:02Z<p>Apisa: /* Spring 2024 */</p>
<hr />
<div>During the Spring 2024 semester, '''RTG / Group Actions and Dynamics''' seminar meets in room '''Sterling Hall 3425''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
== Spring 2024 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 22<br />
|[https://sites.google.com/view/aaron-messerla/ Aaron Messerla] (UIC)<br />
|Quasi-isometries of relatively hyperbolic groups with an elementary hierarchy<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|January 24 (1pm in VV 901)<br />
|[https://mitul-islam.github.io/ Mitul Islam] (Max-Planck-Institut)<br />
|Morse-ness in convex projective geometry<br />
|Zimmer<br />
|<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|Rational surface groups on the Hitchin component<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|Bootstrapping dynamics in the moduli space of non-orientable surfaces<br />
|Uyanik<br />
|<br />
|-<br />
|February 12<br />
|[https://www.noellesawyer.com Noelle Sawyer] (Southwestern)<br />
|Unique Equilibrium States for Geodesic Flows<br />
|Loving, Uyanik, Work<br />
|<br />
|-<br />
|February 19<br />
|[https://web.math.utk.edu/~yqing/ Yulan Qing] (Tennessee)<br />
|Geometric Boundary of Groups<br />
|Zimmer<br />
|<br />
|-<br />
|February 26<br />
|Blandine Galiay (IHES)<br />
|Divisible convex sets in flag manifolds and rigidity<br />
|Zimmer<br />
|<br />
|-<br />
|March 4<br />
|[http://userhome.brooklyn.cuny.edu/aulicino/ David Aulicino] (Brooklyn College)<br />
|Siegel-Veech Constants of Cyclic Covers of Generic Translation Surfaces<br />
|Apisa<br />
|<br />
|-<br />
|March 11<br />
|[https://aacalderon.com/ Aaron Calderon] (Chicago)<br />
|TBA<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|March 18<br />
|[http://sub.mersion.cc Josh Southerland] (Indiana)<br />
|TBA<br />
|Fisher<br />
|<br />
|-<br />
|April 1<br />
|[http://www.caglaruyanik.com Caglar Uyanik] (UW)<br />
|TBA<br />
|local<br />
|<br />
|-<br />
|April 8<br />
|[https://mabainbr.pages.iu.edu/?_gl=1*r2jhoy*_ga*OTk3MTk0Mzg3LjE3MDQ5OTU1MTA.*_ga_61CH0D2DQW*MTcwNDk5NTYyMy4xLjAuMTcwNDk5NTYyMy42MC4wLjA.&_ga=2.157330302.532468181.1704995624-997194387.1704995510 Matt Bainbridge] (Indiana)<br />
|TBA<br />
|Apisa<br />
|<br />
|-<br />
|April 15<br />
|[https://math.hunter.cuny.edu/ilyakapo/ Ilya Kapovich] (CUNY)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 22<br />
|[https://sites.google.com/view/yuchanchang/ Yu-Chan Chang] (Wesleyan)<br />
|TBA<br />
|Dymarz<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Kent, Loving, Uyanik<br />
|}<br />
<br />
== Spring Abstracts ==<br />
===Aaron Messerla===<br />
<br />
Sela introduced limit groups in his work on the Tarski problem, and showed that each limit group has a cyclic hierarchy. We prove that a class of relatively hyperbolic groups, equipped with a hierarchy similar to the one for limit groups, is closed under quasi-isometry. Additionally, these groups share some of the algebraic properties of limit groups. In this talk I plan to present motivation for and introduce the class of groups studied, as well as present some of the results for this class.<br />
===Mitul Islam===<br />
<br />
The (Hilbert metric) geometry of properly convex domains generalizes real hyperbolic geometry. This generalization is far from the Riemannian notion of non-positive curvature, but they have some intriguing similarities. I will explore this connection from a coarse geometry viewpoint.<br />
The focus will be on Morse geodesics ("negatively curved directions", in a coarse sense) in properly convex domains. I will show that Morse-ness can be characterized entirely using linear algebraic data (i.e. singular values of matrices that track the geodesic). Further, I will discuss how this coarse geometric notion of Morse is related to the symmetric space geometry as well as the smoothness of boundary points. This is joint work with Theodore Weisman.<br />
<br />
===Michael Zshornack===<br />
<br />
Margulis's work on lattices in higher-rank and a number of questions on the existence of surface subgroups motivate the need for understanding arithmetic properties of spaces of surface group representations. In recent work with Jacques Audibert, we outline one possible approach towards understanding such properties for the Hitchin component, one particularly nice space of representations. We utilize the underlying geometry of this space to reduce questions about its arithmetic to questions about the arithmetic of certain algebraic groups, which in turn, allows us to characterize the rational points on these components. In this talk, I'll give an overview of the geometric methods behind the proof of our result and indicate some natural questions about the nature of the resulting surface group actions that follow.<br />
<br />
===Sayantan Khan===<br />
<br />
The moduli spaces of non-orientable hyperbolic surfaces behave significantly differently from their orientable counterparts.<br />
They have infinite volume, almost all geodesic flow orbits escape off to infinity, and the growth of mapping class group orbit points and simple closed curves is believed to have non-integer exponents, unlike in the orientable setting.<br />
In this talk, we outline some of the oddities of these moduli spaces, and outline an approach for studying the dynamics on these spaces via Patterson-Sullivan theory.<br />
A key obstruction to imitating the techniques from the orientable setting is that a number of these techniques rely on the dynamics of the geodesic flow and the mapping class group action on Teichmüller spaces of orientable surfaces, which is not something we can do in the non-orientable setting, since that is what we are trying to prove.<br />
The way around these obstructions is by proving weaker versions of these dynamical statements using a dynamics free approach, which we then use to bootstrap the stronger results.<br />
<br />
===Noelle Sawyer===<br />
<br />
In this talk I will discuss some known results about the geodesics and equilibrium states of the geodesic flow in negative curvature. After, I will introduce some of the tools and techniques needed to show the uniqueness of equilibrium states in the setting of translation surfaces. If time allows, I will talk about some of our upcoming work about the Bernoulli property. This is joint work with Benjamin Call, Dave Constantine, Alena Erchenko, and Grace Work. <br />
<br />
<br />
<br />
===Yulan Qing===<br />
<br />
Gromov boundary provides a useful compactification for all infinite-diameter Gromov hyperbolic spaces. It consists of all geodesic rays starting at a given base-point and it is an essential tool in the study of the coarse geometry of hyperbolic groups. In this talk we generalize the Gromov boundary. We first construct the sublinearly Morse boundaries and show that it is a QI-invariant, metrizable topological space. We show sublinearly Morse directions are generic both in the sense of Patterson-Sullivan and in the sense of random walk. <br />
<br />
The sublinearly Morse boundaries are subsets of all directions with desired properties. In the second half of the talk, we will truly consider the space of all directions and show that with some minimal assumptions on the space, the resulting boundary is a QI-invariant topology space in which many existing boundaries are embedded. This talk is based on a series of work with Kasra Rafi and Giulio Tiozzo.<br />
<br />
===Blandine Galiay===<br />
<br />
Divisible convex sets have been widely studied since the 1960s. They are proper domains of the projective space that admit a cocompact action of a discrete subgroup of the linear projective group. The best-known examples are symmetric spaces embedded in the projective space, but there are also many nonsymmetric examples. It is natural to seek to generalize this theory, by replacing the projective space by a flag variety G/P, where G is a real semisimple non-compact Lie group and P a parabolic of G. A question of van Limbeek and Zimmer is then: are there examples of divisible convex sets in G/P that are nonsymmetric? In a number of cases, it has been proved that there are not. In this talk, we will focus on some particular classes of flag varieties in which rigidity can indeed be observed.<br />
<br />
===David Aulicino===<br />
===Aaron Calderon===<br />
===Josh Southerland===<br />
===Caglar Uyanik===<br />
===Matt Bainbridge===<br />
===Ilya Kapovich===<br />
===Yu-Chan Chang===<br />
===Chris Leininger===<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|Periodic points of Prym eigenforms<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|Non-planarity of SL(2,Z)-orbits of origamis<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|Colloquium by [https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] at 4pm<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
Origamis (also known as square-tiled surfaces) arise naturally in a variety of settings in low-dimensional topology. They can be thought of as generalisations of the torus (the unit square with opposite sides glued) since they are surfaces obtained by gluing the opposite sides of a collection of unit squares. There is a natural action of the matrix group SL(2,Z) on origamis. In genus two (with some extra conditions) the orbits of this action were classified by Hubert-Lelièvre and McMullen. By considering a generating set of size two for SL(2,Z) and varying the number of squares used to build the origamis, we can turn these orbits into an infinite family of four-valent graphs. It is a long-standing conjecture of McMullen that these orbit graphs form a family of expander graphs. In this talk, giving indirect evidence for this conjecture, I will discuss joint work with Carlos Matheus in which we show that these orbit graphs are eventually non-planar - a requirement of any family of expander graphs.<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam-022124.pdf&diff=26187File:Putnam-022124.pdf2024-02-21T02:41:34Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club&diff=26186Putnam Club2024-02-21T02:41:13Z<p>Apisa: </p>
<hr />
<div>[[File:Bascom-fall-1500x500-1500x500.jpg]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2024 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Laurel Ohm </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (first meeting on Jan 31st) in Van Vleck B325 for some challenging questions, pizza and soda!!!'''<br />
<br />
In the spring, the UW holds our own in-house Undergraduate Math Contest. It is (tentatively) scheduled for Saturday, April 13th. <br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old Putnam exams and more information on the Putnam competition.] The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students.</div><br />
<div style="text-align: center;">[[Putnam Club Archive | The archive of the Putnam Club from past years, with many practice problems.]]</div><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | January 31<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Assorted algebra problems<br />
|-<br />
| bgcolor="#D0D0D0" | February 7<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBD<br />
|-<br />
| bgcolor="#D0D0D0" | February 14<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-021424.pdf|Multivariable Calculus]].<br />
|-<br />
| bgcolor="#D0D0D0" | February 21<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-022124.pdf|Polynomials]].<br />
|-<br />
|}<br />
</center><br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">Fall 2023</div></font></span><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | September 27<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Introductory meeting - [[Media:Putnam-092723.pdf|assorted problems]].<br />
|-<br />
| bgcolor="#D0D0D0" | October 4<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Polynomials]].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 11<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | [https://drive.google.com/file/d/1yonONnXcFyI7VRaAyqnYodZuJIXoTfrJ/view?usp=drive_link Calculus problems].<br />
|-<br />
| bgcolor="#D0D0D0" | October 18<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | Even numbered problems from last time and [https://drive.google.com/file/d/1fe4Dxp7w3C3u5IvnM-U11dVyCWL1S0DA/view?usp=drive_link additional calculus problems]<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 25<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-102523.pdf|Number theory]].<br />
|-<br />
| bgcolor="#D0D0D0" | November 1<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Let us try something different today: a mock math contest. Let's look at a past [https://intranet.math.vt.edu/vtrmc/exams/37th%20VTRMC.pdf Virginia Tech Contests].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 8<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Probability<br />
|-<br />
| bgcolor="#D0D0D0" | November 15<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Combinatorics<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 22<br />
| <br />
| No meeting (Wednesday before Thanksgiving)<br />
|-<br />
<br />
<br />
| bgcolor="#D0D0D0" | November 29<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-112923.pdf|Geometry]].<br />
|-<br />
| bgcolor="#D0D0D0" | December 6<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | Putnam review<br />
|-<br />
|}<br />
</center></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club&diff=26118Putnam Club2024-02-13T23:44:01Z<p>Apisa: </p>
<hr />
<div>[[File:Bascom-fall-1500x500-1500x500.jpg]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2024 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Laurel Ohm </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (first meeting on Jan 31st) in Van Vleck B325 for some challenging questions, pizza and soda!!!'''<br />
<br />
In the spring, the UW holds our own in-house Undergraduate Math Contest. It is (tentatively) scheduled for Saturday, April 13th. <br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old Putnam exams and more information on the Putnam competition.] The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students.</div><br />
<div style="text-align: center;">[[Putnam Club Archive | The archive of the Putnam Club from past years, with many practice problems.]]</div><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | January 31<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Assorted algebra problems<br />
|-<br />
| bgcolor="#D0D0D0" | February 7<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBD<br />
|-<br />
| bgcolor="#D0D0D0" | February 14<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-021424.pdf|Multivariable Calculus]].<br />
|-<br />
| bgcolor="#D0D0D0" | February 21<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | TBD<br />
|-<br />
|}<br />
</center><br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">Fall 2023</div></font></span><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | September 27<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Introductory meeting - [[Media:Putnam-092723.pdf|assorted problems]].<br />
|-<br />
| bgcolor="#D0D0D0" | October 4<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Polynomials]].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 11<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | [https://drive.google.com/file/d/1yonONnXcFyI7VRaAyqnYodZuJIXoTfrJ/view?usp=drive_link Calculus problems].<br />
|-<br />
| bgcolor="#D0D0D0" | October 18<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | Even numbered problems from last time and [https://drive.google.com/file/d/1fe4Dxp7w3C3u5IvnM-U11dVyCWL1S0DA/view?usp=drive_link additional calculus problems]<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 25<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-102523.pdf|Number theory]].<br />
|-<br />
| bgcolor="#D0D0D0" | November 1<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Let us try something different today: a mock math contest. Let's look at a past [https://intranet.math.vt.edu/vtrmc/exams/37th%20VTRMC.pdf Virginia Tech Contests].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 8<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Probability<br />
|-<br />
| bgcolor="#D0D0D0" | November 15<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Combinatorics<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 22<br />
| <br />
| No meeting (Wednesday before Thanksgiving)<br />
|-<br />
<br />
<br />
| bgcolor="#D0D0D0" | November 29<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-112923.pdf|Geometry]].<br />
|-<br />
| bgcolor="#D0D0D0" | December 6<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | Putnam review<br />
|-<br />
|}<br />
</center></div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam-021424.pdf&diff=26117File:Putnam-021424.pdf2024-02-13T23:43:24Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club&diff=26116Putnam Club2024-02-13T23:40:47Z<p>Apisa: </p>
<hr />
<div>[[File:Bascom-fall-1500x500-1500x500.jpg]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2024 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Laurel Ohm </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (first meeting on Jan 31st) in Van Vleck B325 for some challenging questions, pizza and soda!!!'''<br />
<br />
In the spring, the UW holds our own in-house Undergraduate Math Contest. It is (tentatively) scheduled for Saturday, April 13th. <br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old Putnam exams and more information on the Putnam competition.] The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students.</div><br />
<div style="text-align: center;">[[Putnam Club Archive | The archive of the Putnam Club from past years, with many practice problems.]]</div><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | January 31<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Assorted algebra problems<br />
|-<br />
| bgcolor="#D0D0D0" | February 7<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBD<br />
|-<br />
| bgcolor="#D0D0D0" | February 14<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Multivariable Calculus]].<br />
|-<br />
| bgcolor="#D0D0D0" | February 21<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | TBD<br />
|-<br />
|}<br />
</center><br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">Fall 2023</div></font></span><br />
<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | September 27<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Introductory meeting - [[Media:Putnam-092723.pdf|assorted problems]].<br />
|-<br />
| bgcolor="#D0D0D0" | October 4<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Polynomials]].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 11<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | [https://drive.google.com/file/d/1yonONnXcFyI7VRaAyqnYodZuJIXoTfrJ/view?usp=drive_link Calculus problems].<br />
|-<br />
| bgcolor="#D0D0D0" | October 18<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | Even numbered problems from last time and [https://drive.google.com/file/d/1fe4Dxp7w3C3u5IvnM-U11dVyCWL1S0DA/view?usp=drive_link additional calculus problems]<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 25<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-102523.pdf|Number theory]].<br />
|-<br />
| bgcolor="#D0D0D0" | November 1<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Let us try something different today: a mock math contest. Let's look at a past [https://intranet.math.vt.edu/vtrmc/exams/37th%20VTRMC.pdf Virginia Tech Contests].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 8<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Probability<br />
|-<br />
| bgcolor="#D0D0D0" | November 15<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | Combinatorics<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 22<br />
| <br />
| No meeting (Wednesday before Thanksgiving)<br />
|-<br />
<br />
<br />
| bgcolor="#D0D0D0" | November 29<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-112923.pdf|Geometry]].<br />
|-<br />
| bgcolor="#D0D0D0" | December 6<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | Putnam review<br />
|-<br />
|}<br />
</center></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Group_Actions_and_Dynamics_Seminar&diff=25865Group Actions and Dynamics Seminar2024-01-11T17:54:01Z<p>Apisa: /* Spring 2024 */</p>
<hr />
<div>During the Spring 2024 semester, '''RTG / Group Actions and Dynamics''' seminar meets in room '''Sterling Hall 3425''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
== Spring 2024 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 22<br />
|[https://sites.google.com/view/aaron-messerla/ Aaron Messerla] (UIC)<br />
|TBA<br />
|Dymarz and Uyanik<br />
|<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|February 12<br />
|[https://www.noellesawyer.com Noelle Sawyer] (Southwestern)<br />
|TBA<br />
|Loving, Uyanik, Work<br />
|<br />
|-<br />
|February 19<br />
|[https://web.math.utk.edu/~yqing/ Yulan Qing] (Tennessee)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 26<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|March 4<br />
|[http://userhome.brooklyn.cuny.edu/aulicino/ David Aulicino] (Brooklyn College)<br />
|TBA<br />
|Apisa<br />
|<br />
|-<br />
|March 11<br />
|[https://aacalderon.com/ Aaron Calderon] (Chicago)<br />
|TBA<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|March 18<br />
|[http://sub.mersion.cc Josh Southerland] (Indiana)<br />
|TBA<br />
|Fisher<br />
|<br />
|-<br />
|April 1<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|April 8<br />
|[https://mabainbr.pages.iu.edu/?_gl=1*r2jhoy*_ga*OTk3MTk0Mzg3LjE3MDQ5OTU1MTA.*_ga_61CH0D2DQW*MTcwNDk5NTYyMy4xLjAuMTcwNDk5NTYyMy42MC4wLjA.&_ga=2.157330302.532468181.1704995624-997194387.1704995510 Matt Bainbridge] (Indiana)<br />
|TBA<br />
|Apisa<br />
|<br />
|-<br />
|April 15<br />
|[https://math.hunter.cuny.edu/ilyakapo/ Ilya Kapovich] (CUNY)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 22<br />
|[https://sites.google.com/view/yuchanchang/ Yu-Chan Chang] (Wesleyan)<br />
|TBA<br />
|Dymarz<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Kent, Loving, Uyanik<br />
|}<br />
<br />
== Spring Abstracts ==<br />
===Aaron Messerla===<br />
===Michael Zshornack===<br />
===Sayantan Khan===<br />
===Noelle Sawyer===<br />
===Yulan Qing===<br />
===David Aulicino===<br />
===Aaron Calderon===<br />
===Josh Southerland===<br />
===Ilya Kapovich===<br />
===Yu-Chan Chang===<br />
===Chris Leininger===<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|Periodic points of Prym eigenforms<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|Non-planarity of SL(2,Z)-orbits of origamis<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|Colloquium by [https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] at 4pm<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
Origamis (also known as square-tiled surfaces) arise naturally in a variety of settings in low-dimensional topology. They can be thought of as generalisations of the torus (the unit square with opposite sides glued) since they are surfaces obtained by gluing the opposite sides of a collection of unit squares. There is a natural action of the matrix group SL(2,Z) on origamis. In genus two (with some extra conditions) the orbits of this action were classified by Hubert-Lelièvre and McMullen. By considering a generating set of size two for SL(2,Z) and varying the number of squares used to build the origamis, we can turn these orbits into an infinite family of four-valent graphs. It is a long-standing conjecture of McMullen that these orbit graphs form a family of expander graphs. In this talk, giving indirect evidence for this conjecture, I will discuss joint work with Carlos Matheus in which we show that these orbit graphs are eventually non-planar - a requirement of any family of expander graphs.<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25789Dynamics Seminar2024-01-04T18:12:44Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Sterling Hall 1339''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
== Spring 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 22<br />
|[https://sites.google.com/view/aaron-messerla/ Aaron Messerla] (UIC)<br />
|TBA<br />
|Dymarz and Uyanik<br />
|<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|February 12<br />
|[https://www.noellesawyer.com Noelle Sawyer] (Southwestern)<br />
|TBA<br />
|Loving, Uyanik, Work<br />
|<br />
|-<br />
|February 19<br />
|[https://web.math.utk.edu/~yqing/ Yulan Qing] (Tennessee)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 26<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|March 4<br />
|[http://userhome.brooklyn.cuny.edu/aulicino/ David Aulicino] (Brooklyn College)<br />
|<br />
|<br />
|<br />
|-<br />
|March 11<br />
|[https://aacalderon.com/ Aaron Calderon] (Chicago)<br />
|TBA<br />
|Loving and Uyanik<br />
|<br />
|-<br />
|March 18<br />
|[http://sub.mersion.cc Josh Southerland] (Indiana)<br />
|TBA<br />
|Fisher<br />
|<br />
|-<br />
|April 1<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|April 8<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|April 15<br />
|[https://math.hunter.cuny.edu/ilyakapo/ Ilya Kapovich] (CUNY)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 22<br />
|[https://sites.google.com/view/yuchanchang/ Yu-Chan Chang] (Wesleyan)<br />
|TBA<br />
|Dymarz<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Kent, Loving, Uyanik<br />
|}<br />
<br />
== Spring Abstracts ==<br />
===Aaron Messerla===<br />
===Michael Zshornack===<br />
===Sayantan Khan===<br />
===Noelle Sawyer===<br />
===Yulan Qing===<br />
=== Aaron Calderon ===<br />
===Josh Southerland===<br />
===Ilya Kapovich===<br />
===Yu-Chan Chang===<br />
===Chris Leininger===<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|Periodic points of Prym eigenforms<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|Non-planarity of SL(2,Z)-orbits of origamis<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|Colloquium by [https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] at 4pm<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
Origamis (also known as square-tiled surfaces) arise naturally in a variety of settings in low-dimensional topology. They can be thought of as generalisations of the torus (the unit square with opposite sides glued) since they are surfaces obtained by gluing the opposite sides of a collection of unit squares. There is a natural action of the matrix group SL(2,Z) on origamis. In genus two (with some extra conditions) the orbits of this action were classified by Hubert-Lelièvre and McMullen. By considering a generating set of size two for SL(2,Z) and varying the number of squares used to build the origamis, we can turn these orbits into an infinite family of four-valent graphs. It is a long-standing conjecture of McMullen that these orbit graphs form a family of expander graphs. In this talk, giving indirect evidence for this conjecture, I will discuss joint work with Carlos Matheus in which we show that these orbit graphs are eventually non-planar - a requirement of any family of expander graphs.<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club&diff=25673Putnam Club2023-11-29T22:41:01Z<p>Apisa: </p>
<hr />
<div>[[File:Bascom-fall-1500x500-1500x500.jpg]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2023 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Laurel Ohm </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 27th) in Van Vleck B325 for some challenging questions, pizza and soda!!!'''<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. This year, the exam is on Saturday, December 2nd. <br />
The exam is run in two three-hour sessions of six problems each. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<div style="text-align: center;">[[Putnam Club Archive | The archive of the Putnam Club from past years, with many practice problems.]]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | September 27<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Introductory meeting - [[Media:Putnam-092723.pdf|assorted problems]].<br />
|-<br />
| bgcolor="#D0D0D0" | October 4<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Polynomials]].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 11<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | [https://drive.google.com/file/d/1yonONnXcFyI7VRaAyqnYodZuJIXoTfrJ/view?usp=drive_link Calculus problems].<br />
|-<br />
| bgcolor="#D0D0D0" | October 18<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | Even numbered problems from last time and [https://drive.google.com/file/d/1fe4Dxp7w3C3u5IvnM-U11dVyCWL1S0DA/view?usp=drive_link additional calculus problems]<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 25<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-102523.pdf|Number theory]].<br />
|-<br />
| bgcolor="#D0D0D0" | November 1<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Let us try something different today: a mock math contest. Let's look at a past [https://intranet.math.vt.edu/vtrmc/exams/37th%20VTRMC.pdf Virginia Tech Contests].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 8<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBA<br />
|-<br />
| bgcolor="#D0D0D0" | November 15<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBA<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 22<br />
| <br />
| No meeting (Wednesday before Thanksgiving)<br />
|-<br />
<br />
<br />
| bgcolor="#D0D0D0" | November 29<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-112923.pdf|Geometry]].<br />
|-<br />
| bgcolor="#D0D0D0" | December 6<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | TBA<br />
|-<br />
|}<br />
</center></div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam-112923.pdf&diff=25672File:Putnam-112923.pdf2023-11-29T22:40:37Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club&diff=25671Putnam Club2023-11-29T22:39:28Z<p>Apisa: </p>
<hr />
<div>[[File:Bascom-fall-1500x500-1500x500.jpg]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2023 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Laurel Ohm </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 27th) in Van Vleck B325 for some challenging questions, pizza and soda!!!'''<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. This year, the exam is on Saturday, December 2nd. <br />
The exam is run in two three-hour sessions of six problems each. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<div style="text-align: center;">[[Putnam Club Archive | The archive of the Putnam Club from past years, with many practice problems.]]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
{|style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" | September 27<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Introductory meeting - [[Media:Putnam-092723.pdf|assorted problems]].<br />
|-<br />
| bgcolor="#D0D0D0" | October 4<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Polynomials]].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 11<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | [https://drive.google.com/file/d/1yonONnXcFyI7VRaAyqnYodZuJIXoTfrJ/view?usp=drive_link Calculus problems].<br />
|-<br />
| bgcolor="#D0D0D0" | October 18<br />
| bgcolor="#D0D0D0" | Laurel Ohm<br />
| bgcolor="yellow" | Even numbered problems from last time and [https://drive.google.com/file/d/1fe4Dxp7w3C3u5IvnM-U11dVyCWL1S0DA/view?usp=drive_link additional calculus problems]<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | October 25<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | [[Media:Putnam-102523.pdf|Number theory]].<br />
|-<br />
| bgcolor="#D0D0D0" | November 1<br />
| bgcolor="#D0D0D0" | Dima Arinkin<br />
| bgcolor="yellow" | Let us try something different today: a mock math contest. Let's look at a past [https://intranet.math.vt.edu/vtrmc/exams/37th%20VTRMC.pdf Virginia Tech Contests].<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 8<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBA<br />
|-<br />
| bgcolor="#D0D0D0" | November 15<br />
| bgcolor="#D0D0D0" | Brian Lawrence<br />
| bgcolor="yellow" | TBA<br />
|-<br />
<br />
| bgcolor="#D0D0D0" | November 22<br />
| <br />
| No meeting (Wednesday before Thanksgiving)<br />
|-<br />
<br />
<br />
| bgcolor="#D0D0D0" | November 29<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | [[Media:Putnam-100423.pdf|Geometry]].<br />
|-<br />
| bgcolor="#D0D0D0" | December 6<br />
| bgcolor="#D0D0D0" | Paul Apisa<br />
| bgcolor="yellow" | TBA<br />
|-<br />
|}<br />
</center></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25613Dynamics Seminar2023-11-20T04:23:01Z<p>Apisa: /* Fall 2023 */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Sterling Hall 1339''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|Periodic points of Prym eigenforms<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
== Spring 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Uyanik<br />
|}<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25612Dynamics Seminar2023-11-20T04:22:30Z<p>Apisa: /* Sam Freedman */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Sterling Hall 1339''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|TBA<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
We will consider the dynamics of affine automorphisms acting on highly symmetric translation surfaces called Veech surfaces. Specifically, we’ll examine the points of the surface that are periodic, i.e., have a finite orbit under the whole automorphism group. While this set is known to be finite for primitive Veech surfaces, for applications it is desirable to determine the periodic points explicitly. In this talk we will discuss our classification of periodic points in the case of minimal Prym eigenforms, certain primitive Veech surfaces in genera 2, 3, and 4.<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
== Spring 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Uyanik<br />
|}<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25608Dynamics Seminar2023-11-18T04:10:13Z<p>Apisa: /* Fall Abstracts */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Sterling Hall 1339''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|TBA<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Sam Freedman===<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
== Spring 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Uyanik<br />
|}<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25607Dynamics Seminar2023-11-18T04:09:26Z<p>Apisa: /* Fall 2023 */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Sterling Hall 1339''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|Whitehead space: a tool to study finite regular covers of graphs<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|Short curves of end-periodic mapping tori<br />
|Loving<br />
|-<br />
|September 28 '''(Thursday 4-5pm in B139)'''<br />
|[https://sites.google.com/view/itamarv/home Itamar Vigdorovich] (Weizmann)<br />
|Group stability, characters, and dynamics on compact groups<br />
|Dymarz/Gurevich<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|Short geodesics with self-intersections<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|Marked Length Spectrum Rigidity for Surface Amalgams<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23 '''(11:55-12:55 in B223)'''<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|Dynamics on the SU(2,1)-character varieties of the one-holed torus<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|A characterization of hyperbolic groups via contracting elements<br />
|Uyanik<br />
|-<br />
|November 6<br />
|<br />
|<br />
|<br />
|-<br />
<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
| A metric view of polynomial shift locus<br />
|Wu<br />
|-<br />
|November 20<br />
||[https://sfreedman67.github.io/ Sam Freedman] (Brown)<br />
|TBA<br />
|Apisa<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|Graphically discrete groups and rigidity<br />
|Uyanik<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
The Whitehead space of a finite regular cover of the rose is a locally infinite graph whose vertices are in one-to-one correspondence with conjugacy classes of elements of the subgroup associated with the cover. Every Whitehead space is a subgraph of the quotient of <math>\mathrm{Cay}(F_n, \mathcal{C})</math> by conjugacy; here $\mathcal{C}$ is the set of elements of $F_n$ conjugate into a proper free factor. Our main interest in this space is that it is connected if and only if the fundamental group of the associated cover is generated by lifts of elements of $\mathcal{C}$ to the cover. In addition, Whitehead space of the rose is an infinite-diameter, non-hyperbolic, one-ended space with an isometric action of $\mathrm{Out}(F_n)$. Thus, Whitehead space is not quasi-isometric to the free factor complex, the free splitting complex, or Outer Space.<br />
<br />
===Brandis Whitfield===<br />
Let $S$ be a boundaryless infinite-type surface with finitely many ends and consider an end-periodic homeomorphism $f$$ $of S. The end-periodicity of $f$ ensures that $M_f$, its associated mapping torus, has a compactification as a $3$-manifold with boundary; and further, if $f$ is atoroidal, then $M_f$ admits a hyperbolic metric.<br />
<br />
As an end-periodic analogy to work of Minsky in the finite-type setting, we show that given a subsurface $Y\subset S$, the subsurface projections between the "positive" and "negative" Handel-Miller laminations provide bounds for the geodesic length of the boundary of $Y$ as it resides in $M_f$.<br />
<br />
In this talk, we'll discuss the motivating theory for finite-type surfaces and closed fibered hyperbolic $3$-manifolds, and how these techniques may be used in the infinite-type setting.<br />
<br />
===Itamar Vigdorovich===<br />
<br />
I will discuss three seemingly unrelated topics:<br />
1. Stability: given a pair of matrices that almost commute, can they be perturbed to matrices which do commute? Interestingly, the answer highly depends on the chosen metric on matrices. This question is a special case of group stability: is every almost-homomorphism close to an actual homomorphism?<br />
2. Characters: these are functions on groups with special properties that generalize the classical notion in Pontryagin's theory of abelian groups, and in Frobenius's theory of finite groups. Is every character a limit of a finite-dimensional character?<br />
3. Topological dynamics: given a group G acting by homeomorphisms on a compact space X, are the periodic measures dense is the space all invariant measures?<br />
In this talk I will present these three subjects of study and explain how there are all in fact intimately related, as least in the amenable setting. For example, stability of the lamplighter group is strongly related to the orbit closing lemma for the Bernoulli shift, and stability of the semidirect product ZxZ[1/6] is related to whether Furstenberg's x2x3 system has dense periodic measures. <br />
The talk is based on a joint work with Arie Levit.<br />
<br />
===Hanh Vo===<br />
<br />
We consider the set of closed geodesics on a hyperbolic surface. Given any non-negative integer k, we are interested in the set of primitive essential closed geodesics with at least k self-intersections. Among these, we investigate those of minimal length. In this talk, we will discuss their self-intersection numbers.<br />
<br />
===Yandi Wu===<br />
<br />
The marked length spectrum of a negatively curved metric space can be thought of as a length assignment to every closed geodesic in the space. A celebrated result by Otal says that metrics on negatively curved closed surfaces are determined completely by their marked length spectra. In my talk, I will discuss my work towards extending Otal’s result to a large class of surface amalgams, which are natural generalizations of surfaces.<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
In this talk we will discuss join work in progress with S. Lawton and F. Palesi on the (relative) SU(2, 1)–character variety for the once-holed torus. We consider the action of the mapping class group and describe a domain of discontinuity for this action, which strictly contains the set of convex-cocompact characters. We will also discuss the connection with the recent work of S. Schlich, and the inspiration behind this project, which lies in the rich theory developed for SL(2, C)–character varieties by Bowditch, Minsky and others. <br />
<br />
===Giulio Tiozzo===<br />
<br />
The notion of contracting element has become central in geometric group theory, <br />
singling out, in an arbitrary metric space, the geodesics which behave like geodesics <br />
in a delta-hyperbolic space. In this work, joint with K. Chawla and I. Choi, we prove <br />
the following characterization of hyperbolic groups: a group is hyperbolic if and only if <br />
the D-contracting elements are generic with respect to counting in the Cayley graph. <br />
<br />
<br />
===Hongming Nie===<br />
<br />
The escaping rates of critical points for polynomials in C[z] induce a continuous and proper map on the moduli space M_d of degree d\ge 2 polynomials. This map has a monotone-light factorization via an intermediate space T_d^* studied by DeMarco and Pilgrim. Restricting on the shift locus S_d of M_d, one obtains the corresponding intermediate space ST_d^*. In this talk, I will relate generic points in S_d to the length functions on the (2d-2)-rose graph and then present an understanding of the natural projectivization of ST_d^* from a metric view. The metric is obtained from thermodynamic metrics on the space of metric graphs. This is a joint work with Yan Mary He.<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
===Emily Stark===<br />
<br />
Rigidity problems in geometric group theory frequently have the following form: if two finitely generated groups share a geometric structure, do they share algebraic structure? We consider two finitely generated groups that are either quasi-isometric or act geometrically on the same proper metric space, and we ask if they are virtually isomorphic. The work of Papasoglu--Whyte demonstrates that infinite-ended groups are quasi-isometrically flexible, but our results show that if you assume a common geometric model, then there is often rigidity. To do this, we introduce the notion of a graphically discrete group, which imposes a discreteness criterion on the automorphism group of any graph the group acts on geometrically. Classic examples of graphically discrete groups include virtually nilpotent groups and fundamental groups of closed hyperbolic manifolds; free groups are non-examples. We will present new examples and demonstrate this property is not a commensurability invariant. We will present rigidity phenomena for free products of graphically discrete groups. This is joint work with Alex Margolis, Sam Shepherd, and Daniel Woodhouse.<br />
<br />
<br />
== Spring 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|January 29<br />
|[https://sites.google.com/view/michael-zshornack/home Michael Zshornack] (UCSB)<br />
|TBA<br />
|Zimmer<br />
|<br />
|-<br />
|February 5<br />
|[https://www.sayantankhan.io Sayantan Khan] (Michigan)<br />
|TBA<br />
|Uyanik<br />
|<br />
|-<br />
|April 29<br />
|[https://sites.google.com/view/chris-leiningers-webpage/home Chris Leininger] (Rice)<br />
|TBA<br />
|Uyanik<br />
|}<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25093Dynamics Seminar2023-08-31T03:15:33Z<p>Apisa: /* Vaibhav Gadre */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Van Vleck B235''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|TBA<br />
|Loving<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|TBA<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 6<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
|TBA<br />
|Wu<br />
|-<br />
|November 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright] (Middlebury)<br />
|TBA<br />
|Dymarz<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|<br />
|<br />
|<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
A quadratic differential on a Riemann surface is equivalent to a half-translation structure on the surface by complex charts with half-translation transitions. The SL(2,R)-action on the complex plane takes half-translations to half-translations and so descends to moduli spaces of quadratic differentials. The diagonal part of the action is the Teichmuller flow. <br />
<br />
<br />
Apart from its intrinsic interest, the dynamics of Teichmuller flow is central to many applications in geometry, topology and dynamics. The Konstevich—Zorich cocycle which records the action of the flow on the absolute homology of the surface, plays a key role.<br />
<br />
<br />
In this talk, I will explain how the flow detects the topology of moduli spaces. Specifically, we will show that the flow group, namely the subgroup generated by almost flow loops, has finite index in the fundamental group. As a corollary, we will prove that the minus and plus (modular) Rauzy—Veech groups have finite index in the fundamental group, answering a question by Yoccoz.<br />
<br />
<br />
Using this, and Filip’s results on algebraic hulls and Zariski closures of modular monodromies, we prove that the Konstevich—Zurich cocycle (separately minus and plus pieces) have a simple Lyapunov spectrum, extending the work of Forni from 2002 and Avila—Viana from 2007.<br />
<br />
===Becky Eastham===<br />
<br />
===Brandis Whitfield===<br />
<br />
===Hanh Vo===<br />
<br />
===Yandi Wu===<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
===Giulio Tiozzo===<br />
<br />
===Emily Stark===<br />
<br />
<br />
===Hongming Nie===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=25092Dynamics Seminar2023-08-31T03:15:15Z<p>Apisa: /* Fall 2023 */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Van Vleck B235''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|Teichmuller flow detects the fundamental group<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|TBA<br />
|Loving<br />
|-<br />
|October 2<br />
|[https://hanhv.github.io/ Hanh Vo] (Arizona State)<br />
|TBA<br />
|Dymarz<br />
|-<br />
|October 9<br />
|[https://people.math.wisc.edu/~ywu495/ Yandi Wu] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|Mapping class groups of Infinite graphs — “Big Out(Fn)”<br />
|Loving<br />
|-<br />
|October 23<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 6<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 13<br />
|[https://sites.google.com/view/hmnie/home Hongming Nie] (Stony Brook)<br />
|TBA<br />
|Wu<br />
|-<br />
|November 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright] (Middlebury)<br />
|TBA<br />
|Dymarz<br />
|-<br />
|November 27<br />
|[https://people.math.wisc.edu/~ljeffreys/ Luke Jeffreys] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|December 4<br />
|<br />
|<br />
|<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Vaibhav Gadre===<br />
<br />
===Becky Eastham===<br />
<br />
===Brandis Whitfield===<br />
<br />
===Hanh Vo===<br />
<br />
===Yandi Wu===<br />
<br />
===Sanghoon Kwak===<br />
Surfaces and graphs are closely related; there are many parallels between the mapping class groups of finite-type surfaces and finite graphs, where the mapping class group of a finite graph is the outer automorphism group of a free group of (finite) rank. A recent surge of interest in infinite-type surfaces and their mapping class groups begs a natural question: What is the mapping class group of an “infinite” graph? In this talk, I will explain the answer given by Algom-Kfir and Bestvina and present recent work, joint with George Domat (Rice University), and Hannah Hoganson (University of Maryland), on the coarse geometry of such groups.<br />
<br />
===Sara Maloni===<br />
<br />
===Giulio Tiozzo===<br />
<br />
===Emily Stark===<br />
<br />
<br />
===Hongming Nie===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Luke Jeffreys===<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar&diff=24915Dynamics Seminar2023-06-28T04:58:42Z<p>Apisa: /* Fall 2023 */</p>
<hr />
<div>During the Fall 2023 semester, '''RTG / Group Actions and [[Dynamics]]''' seminar meets in room '''Van Vleck B235''' on '''Mondays''' from '''2:25pm - 3:15pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
== Fall 2023 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 11<br />
|[https://www.maths.gla.ac.uk/~vgadre/ Vaibhav Gadre] (Glasgow)<br />
|TBA<br />
|Apisa<br />
|<br />
|-<br />
|September 18<br />
|[https://sites.google.com/view/beckyeastham/ Becky Eastham] (UW Madison)<br />
|TBA<br />
|local<br />
|-<br />
|September 25<br />
|[https://sites.google.com/view/algebrandis/ Brandis Whitfield] (Temple)<br />
|TBA<br />
|Loving<br />
|-<br />
|October 2<br />
|TBA<br />
|TBA<br />
|<br />
|-<br />
|October 9<br />
|TBA<br />
|TBA<br />
|<br />
|-<br />
|October 16<br />
|[https://www.samkwak.info/ Sanghoon Kwak] (Utah)<br />
|TBA<br />
|Loving<br />
|-<br />
|October 23<br />
|[https://sites.google.com/view/sara-maloni Sara Maloni] (UVA)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|October 30<br />
|[http://www.math.toronto.edu/tiozzo/ Giulio Tiozzo] (Toronto)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 6<br />
|[http://www.estark.net/ Emily Stark] (Wesleyan)<br />
|TBA<br />
|Uyanik<br />
|-<br />
|November 13<br />
|<br />
|<br />
|<br />
|-<br />
|November 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright] (Middlebury)<br />
|TBA<br />
|Dymarz<br />
|-<br />
|November 27<br />
|<br />
|<br />
|<br />
|-<br />
|December 4<br />
|<br />
|<br />
|<br />
|-<br />
|December 11<br />
|<br />
|<br />
|<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Becky Eastham===<br />
<br />
===Brandis Whitfield===<br />
<br />
===Sanghoon Kwak===<br />
<br />
===Sara Maloni===<br />
<br />
===Giulio Tiozzo===<br />
<br />
===Emily Stark===<br />
<br />
===Rose Morris-Wright===<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2022-2023 [[Dynamics_Seminar_2022-2023]]<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24818Putnam Club Archive2023-04-26T19:37:04Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2023 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The seventh UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 15 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/ZrzidVfJJcQ9JZ9NA '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam02012023.pdf|inequalities]].<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|Let's talk about [[Media:Putnam021523.pdf|functional equations]].<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|More on [[Media:Putnam022223.pdf|functional equations]]. Canceled due to severe weather.<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| We will go over Dima's notes from last week<br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| We will talk about some [[Media:Probability2023.pdf|probability problems]].<br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| We will talk about [[Media:Putnam03022023.pdf|analytic techniques]].<br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Dima Arinkin<br />
| Some [[Media:Putnam032923.pdf|(easy-ish?) problems]] to practice the extreme principle.<br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang <br />
| We will talk about some [[Media:Putnam Binomial2023.pdf|binomial and generating series problems]]<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| We will continue to work on the set of problems from last week. <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|Let's talk about the problems from the last [[Media:UWUMC23.pdf|UW Undergraduate Math Competition]]<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam04262023.pdf|combinatorial configurations]].<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
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<center><br />
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{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
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<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
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|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
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{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam04262023.pdf&diff=24817File:Putnam04262023.pdf2023-04-26T19:36:04Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam03022023.pdf&diff=24689File:Putnam03022023.pdf2023-03-23T04:34:10Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24688Putnam Club Archive2023-03-23T04:33:39Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2023 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam02012023.pdf|inequalities]].<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|Let's talk about [[Media:Putnam021523.pdf|functional equations]].<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|More on [[Media:Putnam022223.pdf|functional equations]]. Canceled due to severe weather.<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| We will go over Dima's notes from last week<br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| We will talk about some [[Media:Probability2023.pdf|probability problems]].<br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| We will talk about [[Media:Putnam03022023.pdf|analytic techniques]].<br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Dima Arinkin<br />
| <br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang<br />
|<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Paul Apisa<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24687Putnam Club Archive2023-03-23T04:30:50Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Spring 2023 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam02012023.pdf|inequalities]].<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|Let's talk about [[Media:Putnam021523.pdf|functional equations]].<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|More on [[Media:Putnam022223.pdf|functional equations]]. Canceled due to severe weather.<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| We will go over Dima's notes from last week<br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| We will talk about some [[Media:Probability2023.pdf|probability problems]].<br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Dima Arinkin<br />
| <br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang<br />
|<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Paul Apisa<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24572Dynamics Seminar 2022-20232023-03-01T19:14:37Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''End-periodic homeomorphisms and volumes of mapping tori'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''Hurwitz Spaces, Hecke Actions, and Orbit Closures in Moduli Space'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli|Surface group representations inside PSL(n,C) and their shear-bend coordinates]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|[[#Samantha Fairchild|''Pairs in discrete lattice orbits with applications to Veech surfaces'']]<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik and Zhu<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
In this talk, I will discuss the geometry of mapping tori which arise from end-periodic homeomorphisms of infinite-type surfaces. In particular, I will give bounds on the volume of these 3-manifolds in terms of the dynamics of the end-periodic map. I will show how the upper bound on volume utilizes tools of subsurface projections, the geometry of the curve complex, and will present the construction of our model manifold. I will also discuss ongoing work on the lower bound which relies on the machinery of pleated surfaces, suitably adapted to our setting of infinite-type surfaces. This talk represents joint work with Autumn Kent, Heejoung Kim, Chris Leininger, and Marissa Loving (in various configurations).<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
The moduli space of Riemann surfaces is an orbifold whose points correspond to the ways to endow a surface with a complex structure (or hyperbolic metric if you prefer). This is a rich object whose fundamental group is the mapping class group. It comes equipped with a natural metric, called the Teichmuller metric, which determines an action of geodesic flow on the cotangent bundle. This flow and multiplication by elements of C* combine to form a GL(2,R) action.<br />
<br />
However, the closures of these GL(2, R) orbits are mysterious.<br />
<br />
Work of Eskin, Mirzakhani, Mohammadi, and Filip implies that every one is an algebraic variety. But, aside from two well-understood constructions (one of which entails considering loci of covers; the second of which only works, so far, in genus at most 6), there are only 3 known families of orbit closures - the (infinite family of) Bouw-Moller examples, the 6 Eskin-McMullen-Mukamel-Wright (EMMW) examples, and 3 so-called “sporadic” examples. Building off of ideas of Delecroix, Rueth, and Wright, I will describe work showing that the Bouw-Moller and EMMW examples are both examples of orbit closures that can be constructed using the representation theory of finite groups. The main idea will be to connect these examples to Hurwitz spaces of G-regular covers of the sphere (for an appropriate finite group G) and apply a construction of Ellenberg for finding endomorphisms of the Jacobians of the corresponding Riemann surfaces. In the end, I will describe a construction that inputs a finite group G and a set of generators of G satisfying a combinatorial condition and outputs a GL(2, R) orbit closure.<br />
<br />
No background on dynamics on moduli space, Hurwitz spaces, or Riemann surfaces will be assumed.<br />
<br />
===Filippo Mazzoli===<br />
Since their introduction by Thurston, equivariant pleated surfaces have been extremely useful in the investigation of the geometry of hyperbolic 3-manifolds and the space of surface groups representations inside PSL(2,C). In this talk we will present a generalization of the notion of pleated surface and its associated shear-bend coordinates that is particularly well suited for the study of closed surface group representations in PSL(d,C), and we will introduce a corresponding extension of Bonahon’s holomorphic shear-bend parametrization to any d ≥ 2. This is joint work with Sara Maloni, Giuseppe Martone, and Tengren Zhang.<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
Given a discrete subgroup in SL(2,R), we consider discrete orbits of this subgroup under the linear action on the Euclidean plane. For example the orbit SL(2,Z) acting on the first basis vector (1,0) gives a subset of the integer lattice. Understanding the distribution of these discrete subgroups is a venerable problem going back to Gauss with the study of the Gauss circle problem and popularized through the study of the geometry of numbers in the mid to late 1900's. We will give a Siegel--Veech type integral formula for averages of pairs of discrete lattice orbits. The applications of this formula will focus on Veech surfaces, which are certain surfaces given by polygons in the plane with opposite sides identified. A classical example of a translation surface is the torus presented as a unit square in the plane with opposite sides identified. We'll present the general theory through focusing on the examples of the torus and my other favorite translation surface: the Golden L. This talk is based on work with Claire Burrin with a dynamics application by Jon Chaika.<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24571Dynamics Seminar 2022-20232023-03-01T19:13:05Z<p>Apisa: /* Spring Abstracts */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''End-periodic homeomorphisms and volumes of mapping tori'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''Hurwitz Spaces, Hecke Actions, and Orbit Closures in Moduli Space'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli|Surface group representations inside PSL(n,C) and their shear-bend coordinates]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|Pairs in discrete lattice orbits with applications to Veech surfaces<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik and Zhu<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
In this talk, I will discuss the geometry of mapping tori which arise from end-periodic homeomorphisms of infinite-type surfaces. In particular, I will give bounds on the volume of these 3-manifolds in terms of the dynamics of the end-periodic map. I will show how the upper bound on volume utilizes tools of subsurface projections, the geometry of the curve complex, and will present the construction of our model manifold. I will also discuss ongoing work on the lower bound which relies on the machinery of pleated surfaces, suitably adapted to our setting of infinite-type surfaces. This talk represents joint work with Autumn Kent, Heejoung Kim, Chris Leininger, and Marissa Loving (in various configurations).<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
The moduli space of Riemann surfaces is an orbifold whose points correspond to the ways to endow a surface with a complex structure (or hyperbolic metric if you prefer). This is a rich object whose fundamental group is the mapping class group. It comes equipped with a natural metric, called the Teichmuller metric, which determines an action of geodesic flow on the cotangent bundle. This flow and multiplication by elements of C* combine to form a GL(2,R) action.<br />
<br />
However, the closures of these GL(2, R) orbits are mysterious.<br />
<br />
Work of Eskin, Mirzakhani, Mohammadi, and Filip implies that every one is an algebraic variety. But, aside from two well-understood constructions (one of which entails considering loci of covers; the second of which only works, so far, in genus at most 6), there are only 3 known families of orbit closures - the (infinite family of) Bouw-Moller examples, the 6 Eskin-McMullen-Mukamel-Wright (EMMW) examples, and 3 so-called “sporadic” examples. Building off of ideas of Delecroix, Rueth, and Wright, I will describe work showing that the Bouw-Moller and EMMW examples are both examples of orbit closures that can be constructed using the representation theory of finite groups. The main idea will be to connect these examples to Hurwitz spaces of G-regular covers of the sphere (for an appropriate finite group G) and apply a construction of Ellenberg for finding endomorphisms of the Jacobians of the corresponding Riemann surfaces. In the end, I will describe a construction that inputs a finite group G and a set of generators of G satisfying a combinatorial condition and outputs a GL(2, R) orbit closure.<br />
<br />
No background on dynamics on moduli space, Hurwitz spaces, or Riemann surfaces will be assumed.<br />
<br />
===Filippo Mazzoli===<br />
Since their introduction by Thurston, equivariant pleated surfaces have been extremely useful in the investigation of the geometry of hyperbolic 3-manifolds and the space of surface groups representations inside PSL(2,C). In this talk we will present a generalization of the notion of pleated surface and its associated shear-bend coordinates that is particularly well suited for the study of closed surface group representations in PSL(d,C), and we will introduce a corresponding extension of Bonahon’s holomorphic shear-bend parametrization to any d ≥ 2. This is joint work with Sara Maloni, Giuseppe Martone, and Tengren Zhang.<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
Given a discrete subgroup in SL(2,R), we consider discrete orbits of this subgroup under the linear action on the Euclidean plane. For example the orbit SL(2,Z) acting on the first basis vector (1,0) gives a subset of the integer lattice. Understanding the distribution of these discrete subgroups is a venerable problem going back to Gauss with the study of the Gauss circle problem and popularized through the study of the geometry of numbers in the mid to late 1900's. We will give a Siegel--Veech type integral formula for averages of pairs of discrete lattice orbits. The applications of this formula will focus on Veech surfaces, which are certain surfaces given by polygons in the plane with opposite sides identified. A classical example of a translation surface is the torus presented as a unit square in the plane with opposite sides identified. We'll present the general theory through focusing on the examples of the torus and my other favorite translation surface: the Golden L. This talk is based on work with Claire Burrin with a dynamics application by Jon Chaika.<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24570Dynamics Seminar 2022-20232023-03-01T19:12:37Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''End-periodic homeomorphisms and volumes of mapping tori'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''Hurwitz Spaces, Hecke Actions, and Orbit Closures in Moduli Space'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli|Surface group representations inside PSL(n,C) and their shear-bend coordinates]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|Pairs in discrete lattice orbits with applications to Veech surfaces<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik and Zhu<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
In this talk, I will discuss the geometry of mapping tori which arise from end-periodic homeomorphisms of infinite-type surfaces. In particular, I will give bounds on the volume of these 3-manifolds in terms of the dynamics of the end-periodic map. I will show how the upper bound on volume utilizes tools of subsurface projections, the geometry of the curve complex, and will present the construction of our model manifold. I will also discuss ongoing work on the lower bound which relies on the machinery of pleated surfaces, suitably adapted to our setting of infinite-type surfaces. This talk represents joint work with Autumn Kent, Heejoung Kim, Chris Leininger, and Marissa Loving (in various configurations).<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
The moduli space of Riemann surfaces is an orbifold whose points correspond to the ways to endow a surface with a complex structure (or hyperbolic metric if you prefer). This is a rich object whose fundamental group is the mapping class group. It comes equipped with a natural metric, called the Teichmuller metric, which determines an action of geodesic flow on the cotangent bundle. This flow and multiplication by elements of C* combine to form a GL(2,R) action.<br />
<br />
However, the closures of these GL(2, R) orbits are mysterious.<br />
<br />
Work of Eskin, Mirzakhani, Mohammadi, and Filip implies that every one is an algebraic variety. But, aside from two well-understood constructions (one of which entails considering loci of covers; the second of which only works, so far, in genus at most 6), there are only 3 known families of orbit closures - the (infinite family of) Bouw-Moller examples, the 6 Eskin-McMullen-Mukamel-Wright (EMMW) examples, and 3 so-called “sporadic” examples. Building off of ideas of Delecroix, Rueth, and Wright, I will describe work showing that the Bouw-Moller and EMMW examples are both examples of orbit closures that can be constructed using the representation theory of finite groups. The main idea will be to connect these examples to Hurwitz spaces of G-regular covers of the sphere (for an appropriate finite group G) and apply a construction of Ellenberg for finding endomorphisms of the Jacobians of the corresponding Riemann surfaces. In the end, I will describe a construction that inputs a finite group G and a set of generators of G satisfying a combinatorial condition and outputs a GL(2, R) orbit closure.<br />
<br />
No background on dynamics on moduli space, Hurwitz spaces, or Riemann surfaces will be assumed.<br />
<br />
===Filippo Mazzoli===<br />
Since their introduction by Thurston, equivariant pleated surfaces have been extremely useful in the investigation of the geometry of hyperbolic 3-manifolds and the space of surface groups representations inside PSL(2,C). In this talk we will present a generalization of the notion of pleated surface and its associated shear-bend coordinates that is particularly well suited for the study of closed surface group representations in PSL(d,C), and we will introduce a corresponding extension of Bonahon’s holomorphic shear-bend parametrization to any d ≥ 2. This is joint work with Sara Maloni, Giuseppe Martone, and Tengren Zhang.<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24545Dynamics Seminar 2022-20232023-02-24T18:38:30Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''End-periodic homeomorphisms and volumes of mapping tori'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''Hurwitz Spaces, Hecke Actions, and Orbit Closures in Moduli Space'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli| TBA]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|TBA<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik and Zhu<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
In this talk, I will discuss the geometry of mapping tori which arise from end-periodic homeomorphisms of infinite-type surfaces. In particular, I will give bounds on the volume of these 3-manifolds in terms of the dynamics of the end-periodic map. I will show how the upper bound on volume utilizes tools of subsurface projections, the geometry of the curve complex, and will present the construction of our model manifold. I will also discuss ongoing work on the lower bound which relies on the machinery of pleated surfaces, suitably adapted to our setting of infinite-type surfaces. This talk represents joint work with Autumn Kent, Heejoung Kim, Chris Leininger, and Marissa Loving (in various configurations).<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
The moduli space of Riemann surfaces is an orbifold whose points correspond to the ways to endow a surface with a complex structure (or hyperbolic metric if you prefer). This is a rich object whose fundamental group is the mapping class group. It comes equipped with a natural metric, called the Teichmuller metric, which determines an action of geodesic flow on the cotangent bundle. This flow and multiplication by elements of C* combine to form a GL(2,R) action.<br />
<br />
However, the closures of these GL(2, R) orbits are mysterious.<br />
<br />
Work of Eskin, Mirzakhani, Mohammadi, and Filip implies that every one is an algebraic variety. But, aside from two well-understood constructions (one of which entails considering loci of covers; the second of which only works, so far, in genus at most 6), there are only 3 known families of orbit closures - the (infinite family of) Bouw-Moller examples, the 6 Eskin-McMullen-Mukamel-Wright (EMMW) examples, and 3 so-called “sporadic” examples. Building off of ideas of Delecroix, Rueth, and Wright, I will describe work showing that the Bouw-Moller and EMMW examples are both examples of orbit closures that can be constructed using the representation theory of finite groups. The main idea will be to connect these examples to Hurwitz spaces of G-regular covers of the sphere (for an appropriate finite group G) and apply a construction of Ellenberg for finding endomorphisms of the Jacobians of the corresponding Riemann surfaces. In the end, I will describe a construction that inputs a finite group G and a set of generators of G satisfying a combinatorial condition and outputs a GL(2, R) orbit closure.<br />
<br />
No background on dynamics on moduli space, Hurwitz spaces, or Riemann surfaces will be assumed.<br />
<br />
===Filippo Mazzoli===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24544Dynamics Seminar 2022-20232023-02-24T18:37:51Z<p>Apisa: /* Paul Apisa */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''End-periodic homeomorphisms and volumes of mapping tori'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''TBA'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli| TBA]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|TBA<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik and Zhu<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
In this talk, I will discuss the geometry of mapping tori which arise from end-periodic homeomorphisms of infinite-type surfaces. In particular, I will give bounds on the volume of these 3-manifolds in terms of the dynamics of the end-periodic map. I will show how the upper bound on volume utilizes tools of subsurface projections, the geometry of the curve complex, and will present the construction of our model manifold. I will also discuss ongoing work on the lower bound which relies on the machinery of pleated surfaces, suitably adapted to our setting of infinite-type surfaces. This talk represents joint work with Autumn Kent, Heejoung Kim, Chris Leininger, and Marissa Loving (in various configurations).<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
The moduli space of Riemann surfaces is an orbifold whose points correspond to the ways to endow a surface with a complex structure (or hyperbolic metric if you prefer). This is a rich object whose fundamental group is the mapping class group. It comes equipped with a natural metric, called the Teichmuller metric, which determines an action of geodesic flow on the cotangent bundle. This flow and multiplication by elements of C* combine to form a GL(2,R) action.<br />
<br />
However, the closures of these GL(2, R) orbits are mysterious.<br />
<br />
Work of Eskin, Mirzakhani, Mohammadi, and Filip implies that every one is an algebraic variety. But, aside from two well-understood constructions (one of which entails considering loci of covers; the second of which only works, so far, in genus at most 6), there are only 3 known families of orbit closures - the (infinite family of) Bouw-Moller examples, the 6 Eskin-McMullen-Mukamel-Wright (EMMW) examples, and 3 so-called “sporadic” examples. Building off of ideas of Delecroix, Rueth, and Wright, I will describe work showing that the Bouw-Moller and EMMW examples are both examples of orbit closures that can be constructed using the representation theory of finite groups. The main idea will be to connect these examples to Hurwitz spaces of G-regular covers of the sphere (for an appropriate finite group G) and apply a construction of Ellenberg for finding endomorphisms of the Jacobians of the corresponding Riemann surfaces. In the end, I will describe a construction that inputs a finite group G and a set of generators of G satisfying a combinatorial condition and outputs a GL(2, R) orbit closure.<br />
<br />
No background on dynamics on moduli space, Hurwitz spaces, or Riemann surfaces will be assumed.<br />
<br />
===Filippo Mazzoli===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24421Putnam Club Archive2023-02-07T22:51:27Z<p>Apisa: </p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam02012023.pdf|inequalities]].<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang<br />
|<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
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<center><br />
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{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
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<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
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|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
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{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24368Dynamics Seminar 2022-20232023-02-02T21:45:28Z<p>Apisa: /* Spring Abstracts */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''TBA'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''TBA'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli| TBA]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|TBA<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Paul Apisa===<br />
<br />
===Filippo Mazzoli===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=24367Dynamics Seminar 2022-20232023-02-02T21:45:10Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>During the Spring 2023 semester, the [[Dynamics]] seminar meets in room '''2425 of Sterling Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, Chenxi Wu or Andy Zimmer. <br />
<br />
<br />
<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|[http://websites.umich.edu/~blayac/ Pierre-Louis Blayac] (Michigan)<br />
|[[#Pierre-Louis Blayac| ''Divisible convex sets with properly embedded cones'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''Quantitative marked length spectrum rigidity'']]<br />
|Zimmer<br />
|-<br />
|February 13<br />
|[https://sites.google.com/view/elizabeth-field Elizabeth Field] (Utah)<br />
|[[#Elizabeth Field| ''TBA'']]<br />
|Loving<br />
|-<br />
|February 20<br />
|[https://math.berkeley.edu/~chicheuk/ Chi Cheuk Tsang] (Berkeley)<br />
|[[#Chi Cheuk Tsang| ''Dilatations of pseudo-Anosov maps and standardly embedded train tracks'']]<br />
|Loving<br />
|-<br />
|February 27<br />
|[https://people.math.wisc.edu/~apisa/ Paul Apisa] (UW Madison)<br />
|[[#Paul Apisa| ''TBA'']]<br />
|local<br />
|-<br />
|March 6<br />
|[https://filippomazzoli.github.io Filippo Mazzoli] (UVA)<br />
|[[#Filippo Mazzoli| TBA]]<br />
|Zhu<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|[https://www.rosemorriswright.com/ Rose Morris-Wright ] (Middlebury)<br />
|[[#Rose Morris-Wright| ''TBA'']]<br />
|Dymarz<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|TBA<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|April 17<br />
|[https://sites.google.com/view/mikolaj-fraczyk/home Mikolaj Fraczyk] (Chicago)<br />
|[[#Mikolaj Fraczyk| ''TBA'']]<br />
|Skenderi and Zimmer<br />
|-<br />
||April 24<br />
|[https://sites.google.com/view/tarikaougab/home/ Tarik Aougab] (Haverford)<br />
|[[#Tarik Aougab| ''TBA'']]<br />
|Loving<br />
|-<br />
|May 1<br />
|[https://www.dmartinezgranado.com Didac Martinez-Granado] (UC Davis)<br />
|[[#Didac Martinez-Granado| ''TBA'']]<br />
|Uyanik<br />
|-<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
A divisible convex set is a convex, bounded, and open subset of an affine chart of the real projective space, on which acts cocompactly a discrete group of projective transformations. These objects have a very rich theory, which involves ideas from dynamical systems, geometric group theory, (G,X)-structures and Riemannian geometry with nonpositive curvature. Moreover, they are an important source of examples of discrete subgroups of Lie groups; for instance they have links with Anosov representations. In this talk, we will survey known examples of divisible convex sets, and then describe new examples obtained in collaboration with Gabriele Viaggi, of irreducible, non-symmetric, and non-strictly convex divisible convex sets in arbitrary dimensions (at least 3).<br />
<br />
===Karen Butt===<br />
<br />
The marked length spectrum of a closed Riemannian manifold of negative curvature is a function on the free homotopy classes of closed curves which assigns to each class the length of its unique geodesic representative. It is known in certain cases that the marked length spectrum determines the metric up to isometry, and this is conjectured to be true in general. In this talk, we explore to what extent the marked length spectrum on a sufficiently large finite set approximately determines the metric.<br />
<br />
===Elizabeth Field===<br />
<br />
===Chi Cheuk Tsang===<br />
<br />
The dilatation of a pseudo-Anosov map is a measure of the complexity of its dynamics. The minimum dilatation problem asks for the minimum dilatation among all pseudo-Anosov maps defined on a fixed surface, which can be thought of as the smallest amount of mixing one can perform while still doing something topologically interesting. In this talk, we present some recent work on this problem with Eriko Hironaka, which shows a sharp lower bound for dilatations of fully-punctured pseudo-Anosov maps with at least two puncture orbits. We will explain some ideas in the proof, including standardly embedded train tracks and Perron-Frobenius matrices.<br />
<br />
===Caglar Uyanik===<br />
<br />
===Filippo Mazzoli===<br />
<br />
===Rose Morris-Wright===<br />
<br />
===Carolyn Abbott===<br />
<br />
===Samantha Fairchild===<br />
<br />
===Jon Chaika===<br />
<br />
===Mikolaj Fraczyk===<br />
<br />
===Tarik Aougab===<br />
<br />
===Didac Martinez-Granado===<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|postponed<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''Relatively Anosov representations: a dynamical notion of geometric finiteness'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''Pseudo-Anosovs of interval type'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''Classification of critically fixed anti-Thurston maps'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''Revisit the theory of laminar groups'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''Cubulation and Property (T) in random groups'']]<br />
|Dymarz<br />
|-<br />
|December 5<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving|Unmarked simple length spectral rigidity for covers]]<br />
|local<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| '' Intersection number and intersection points of closed geodesics on hyperbolic surfaces'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Feng Zhu===<br />
<br />
Putting hyperbolic metrics on a finite-type surface S gives us linear representations of the fundamental group of S into PSL(2,R) with many nice geometric and dynamical properties: for instance they are discrete and faithful, and in fact stably quasi-isometrically embedded.<br />
<br />
In this talk, we will introduce (relatively) Anosov representations, which generalise this picture to higher-rank Lie groups such as PSL(d,R) for d>2, giving us a class of (relatively) hyperbolic subgroups there with similarly good geometric and dynamical properties.<br />
<br />
This is mostly joint work with Andrew Zimmer.<br />
<br />
===Ethan Farber===<br />
<br />
A pseudo-Anosov (pA) is a homeomorphism of a compact connected surface S that, away from a finite set of points, acts locally as a linear map with one expanding and one contracting eigendirection. Ubiquitous yet mysterious, pAs have fascinated low-dimensional topologists and dynamicists for the past forty years. We show that any pA on the sphere whose associated quadratic differential has at most one zero, admits an invariant train track whose expanding subgraph is an interval. Concretely, such a pA has the dynamics of an interval map. As an application, we recover a uniform lower bound on the entropy of these pAs originally due to Boissy-Lanneau. Time permitting, we will also discuss potential applications to a question of Fried. This is joint work with Karl Winsor.<br />
<br />
===Lukas Geyer===<br />
<br />
Recently there has been an increased interest in complex dynamics of orientation-reversing maps, in particular in the context of gravitational lensing and as an analogue of reflection groups in Sullivan's dictionary between Kleinian groups and dynamics of (anti-)rational maps. Much of the theory parallels the orientation-preserving case, but there are some intriguing differences. In order to deal with the post-critically finite case, we study anti-Thurston maps (orientation-reversing versions of Thurston maps), and prove an orientation-reversing analogue of Thurston's topological classification of post-critically finite rational maps, as well as the canonical decomposition of obstructed maps, following Pilgrim and Selinger. Using these tools, we obtain a combinatorial classification of critically fixed anti-Thurston maps, extending a recently obtained classification of critically fixed anti-rational maps. If time allows, I will explain applications of this classification to gravitational lensing. Most of this is based on joint work with Mikhail Hlushchanka.<br />
<br />
===Harry Baik ===<br />
<br />
I will give a brief introduction to laminar groups which are groups of orientation-preserving homeomorphisms of the circle admitting invariant laminations. The term was coined by Calegari and the study of laminar groups was motivated by work of Thurston and Calegari-Dunfield. We present old and new results on laminar groups which tell us when a given laminar group is either fuchsian or Kleinian. This is based on joint work with KyeongRo Kim and Hongtaek Jung.<br />
<br />
===MurphyKate Montee===<br />
<br />
Random groups are one way to study "typical" behavior of groups. In the Gromov density model, we often find that properties have a threshold density above which the property is satisfied with probability 1, and below which it is satisfied with probability 0. Two properties of random groups that have been well studied are cubulation (and relaxations of this property) and Property (T). In this setting these are mutually exclusive properties, but threshold densities are not known for either property. In this talk I'll present the current state of the art regarding these properties in random groups, and discuss some ways to further these results.<br />
<br />
===Marissa Loving===<br />
A fundamental question in geometry is the extent to which a manifold M is determined by its length spectrum, i.e. the collection of lengths of closed geodesics on M. This has been studied extensively for flat, hyperbolic, and negatively curved metrics. In this talk, we will focus on surfaces equipped with a choice of hyperbolic metric. We will explore the space between (1) work of Otal (resp. Fricke) which asserts that the marked length spectrum (resp. marked ''simple'' length spectrum) determines a hyperbolic surface, and (2) celebrated constructions of Vignéras and Sunada, which show that this rigidity fails when we forget the marking. In particular, we will consider the extent to which the unmarked simple length spectrum distinguishes between hyperbolic surfaces arising from Sunada’s construction. This represents joint work with Tarik Aougab, Max Lahn, and Nick Miller.<br />
<br />
===Tina Torkaman===<br />
<br />
In this talk, I will talk about the (geometric) intersection number between closed geodesics on finite volume hyperbolic surfaces. Specifically, I will discuss the optimum upper bound on the intersection number in terms of the product of hyperbolic lengths. I also talk about the equidistribution of the intersection points between closed geodesics.<br />
<br />
<br />
<br />
<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Whatcha_Doin_Seminar&diff=24366Whatcha Doin Seminar2023-02-02T21:44:01Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>The Whatcha Doin' Seminar is a place where professors can give 20-30 minute talks about their research aimed at beginning graduate students. This will give students an opportunity to meet potential advisors and see what they are up to.<br />
<br />
Time: '''Mondays''' at '''4:30PM'''<br />
<br />
Location: '''Van Vleck B129'''<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |research area<br />
! align="left" |title<br />
|-<br />
|January 30<br />
|Jean-Luc Thiffeault<br />
|Applied Math<br />
|''Active matter''<br />
|-<br />
|February 6<br />
|Dima Arinkin<br />
|Algebraic geometry<br />
|TBA<br />
|-<br />
|February 13<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|February 20<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|February 27<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|March 6<br />
|Paul Apisa<br />
|Dynamics, geometry, topology<br />
|TBA<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|March 27<br />
|Sergey Denisov<br />
|Analysis & PDE<br />
|Title<br />
|-<br />
|April 3<br />
|Andrew Zimmer<br />
|TBA<br />
|TBA<br />
|-<br />
|April 10<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|April 17<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
||April 24<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|May 1<br />
|Marissa Loving<br />
|Geometry, topology, and dynamics<br />
|TBA<br />
|-<br />
|}</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Whatcha_Doin_Seminar&diff=24346Whatcha Doin Seminar2023-02-01T05:47:45Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>The Whatcha Doin' Seminar is a place where professors can give 20-30 minute talks about their research aimed at beginning graduate students. This will give students an opportunity to meet potential advisors and see what they are up to.<br />
<br />
Time: '''Mondays''' at '''4:30PM'''<br />
<br />
Location: '''Van Vleck B129'''<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |research area<br />
! align="left" |title<br />
|-<br />
|January 30<br />
|Jean-Luc Thiffeault<br />
|Applied Math<br />
|''Active matter''<br />
|-<br />
|February 6<br />
|Dima Arinkin<br />
|Algebraic geometry<br />
|TBA<br />
|-<br />
|February 13<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|February 20<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|February 27<br />
|Paul Apisa<br />
|Dynamics, geometry, and topology<br />
|TBA<br />
|-<br />
|March 6<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|March 13<br />
|Spring Break, No Seminar<br />
|<br />
|<br />
|-<br />
|March 20<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|March 27<br />
|Sergey Denisov<br />
|Analysis & PDE<br />
|Title<br />
|-<br />
|April 3<br />
|Andrew Zimmer<br />
|TBA<br />
|TBA<br />
|-<br />
|April 10<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|April 17<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
||April 24<br />
|Speaker<br />
|Subject Area<br />
|Title<br />
|-<br />
|May 1<br />
|Marissa Loving<br />
|Geometry, topology, and dynamics<br />
|TBA<br />
|-<br />
|}</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24345Putnam Club Archive2023-02-01T05:31:46Z<p>Apisa: </p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam02012023.pdf|inequalities]].<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang<br />
|<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam02012023.pdf&diff=24344File:Putnam02012023.pdf2023-02-01T05:30:51Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24328Putnam Club Archive2023-01-31T05:48:01Z<p>Apisa: </p>
<hr />
<div>==Spring 2023==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 1) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting February 1, 2023<br />
Paul Apisa<br />
| We will discuss inequalities.<br />
<br />
|-<br />
|Meeting February 8, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting February 15, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting February 22, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting March 1, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 8, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting March 22, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting March 29, 2023<br />
Paul Apisa<br />
| <br />
<br />
|-<br />
|Meeting April 5, 2023<br />
Botong Wang<br />
|<br />
<br />
|-<br />
|Meeting April 12, 2023<br />
Botong Wang<br />
| <br />
<br />
|-<br />
|Meeting April 19, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting April 26, 2023<br />
Dima Arinkin<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Fall 2022==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, at Van Vleck B107 (9AM-Noon, 2PM-5PM). Make sure to click the link and register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam Club Linear Algebra Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|[[Media:Putnam111622.pdf|Number theory]]!<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
| More number theory ([[Media:Putnam113022.pdf|same worksheet]] with a few more problems).<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=24017Putnam Club Archive2022-11-08T02:14:20Z<p>Apisa: /* Fall 2022 */</p>
<hr />
<div>==Fall 2022==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 83nd Putnam competition] will take place on Saturday, December 3, location to be announced (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam_Club_Linear_Algebra_Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
| We continue to work on the above worksheet.<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=Putnam_Club_Archive&diff=23972Putnam Club Archive2022-11-01T03:55:27Z<p>Apisa: /* Fall 2022 */</p>
<hr />
<div>==Fall 2022==<br />
<br />
[[File:Bascom-fall-1500x500-1500x500.jpg ]] <br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Paul Apisa, Dima Arinkin, Brian Lawrence, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 21) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|-<br />
|Meeting September 21, 2022<br />
Botong Wang<br />
| We will go over some recent [[Media:PutnamProblemsSample.pdf|Putnam problems]] and the [[Media:UWUMC22-update.pdf|Undergraduate math competition problems]].<br />
<br />
|-<br />
|Meeting September 28, 2022<br />
Botong Wang<br />
| We will continue to discuss the problems in the sample set and the latest undergrad math competition.<br />
<br />
|-<br />
|Meeting October 5, 2022<br />
Brian Lawrence<br />
|We will discuss [[Media:Polynomials Oct22.pdf|polynomials]].<br />
<br />
|-<br />
|Meeting October 12, 2022<br />
Brian Lawrence<br />
|We will continue to work on the worksheet from last week. <br />
<br />
|-<br />
|Meeting October 19, 2022<br />
Botong Wang<br />
| We will compute [[Media:Putnam integrals 2022.pdf|integrals]]! The file is updated to include a very nice proof.<br />
<br />
|-<br />
|Meeting October 26, 2022<br />
Botong Wang<br />
| We continue to work on the above worksheet. <br />
<br />
|-<br />
|Meeting November 2, 2022<br />
Paul Apisa<br />
| We will discuss [[Media:Putnam_Club_Linear_Algebra_Techniques.pdf|linear algebra techniques]].<br />
<br />
|-<br />
|Meeting November 9, 2022<br />
Paul Apisa<br />
|<br />
<br />
|-<br />
|Meeting November 16, 2022<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting November 30, 2022<br />
Dima Arinkin<br />
|<br />
<br />
|-<br />
|Meeting December 7, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|-<br />
|Meeting December 14, 2022<br />
Brian Lawrence<br />
|<br />
<br />
|}<br />
</center><br />
<br />
<br />
[[File:WiscFall.jpg ]]<br />
<br />
==Spring 2022==<br />
<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2022 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatyana Shcherbina, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from February 2) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!''' <br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://hilbert.math.wisc.edu/wiki/index.php/Undergraduate_Math_Competition The sixth UW Madison undergraduate math competition] will take place 9am-noon Saturday, April 23 at Van Vleck B115! </font></span><br />
<br />
If you would like to participate in the undergraduate competition, please [https://forms.gle/vnAt3HGxaAR1eF157 '''register here''']. Registration is not required - it is only to help us with organization. <br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting February 2, 2022<br />
Dima Arinkin<br />
|Meeting at the 9th floor lounge Van Vleck. When: February 2, 2022 05:00 PM. <br />
<br />
[[Media:Putnam101415.pdf| Matrices and determinants]]<br />
<br />
|-<br />
|Meeting February 9, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam020922.pdf| Functions and calculus]]<br />
<br />
|-<br />
|Meeting February 16, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 an.pdf| Analysis problems]]<br />
<br />
|-<br />
|Meeting February 23, 2022<br />
Tatyana Shcherbina<br />
|We are going to continue to discuss [[Media:PutClub S22 an2.pdf| Analysis problems 2]]<br />
<br />
|-<br />
|Meeting March 2, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam graph theory 2022 Botong.pdf| Graph theory]]<br />
<br />
|-<br />
|Meeting March 9, 2022<br />
Botong Wang<br />
|We are going to discuss [[Media:Putnam geometry 2022.pdf| Geometry]]<br />
<br />
|-<br />
|Meeting March 23, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam032322.pdf| Games]]<br />
<br />
|-<br />
|Meeting March 30, 2022<br />
Dima Arinkin<br />
| [[Media:Putnam033022.pdf| Generating functions and telescoping series]]<br />
<br />
|-<br />
|Meeting April 6, 2022<br />
Mihaela Ifrim<br />
| [[Media:Competitions-m.pdf| Competition problems]]<br />
<br />
|-<br />
|Meeting April 13, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 compl.pdf| Complex numbers]]<br />
<br />
|-<br />
|Meeting April 20, 2022<br />
Tatyana Shcherbina<br />
|We are going to discuss [[Media:PutClub S22 prob.pdf| Probability problems]]<br />
<br />
|-<br />
|Meeting April 27, 2022<br />
Mihaela Ifrim<br />
|<br />
|}<br />
</center><br />
<br />
<br />
<br />
==Fall 2021==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE Fall 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
'''Join us on Wednesdays 5:00-6:30pm (from September 22) at Van Vleck 9th floor lounge for some challenging questions, pizzas and drinks!!!'''<br />
<br />
<br />
<div style="text-align: center;"><span style="color:blue"><font size="3">[https://www.maa.org/math-competitions/putnam-competition The 82nd Putnam competition] will take place on Saturday, December 4, at Van Vleck B123 (we will move the afternoon exam to B3 floor, most likely B333, due to noise issues) (9AM-Noon, 2PM-5PM). Make sure to register for the competition!!!</font></span><br />
<br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
<div style="text-align: center;">[http://kskedlaya.org/putnam-archive/ Old exams and more information on the Putnam competition.]</div><br />
<br />
'''To sign up for Putnam club email announcements, please send an email to ''putnam-club+join@g-groups.wisc.edu'' (empty subject and body works). '''<br />
<br />
<center><br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting September 22, 2021<br />
Botong Wang<br />
|Meeting at the 9th floor lounge Van Vleck. When: Sep 22, 2021 05:00 PM. <br />
<br />
In the first two lectures, we will take a look at some of the Putnam competition problems from [https://kskedlaya.org/putnam-archive/2020.pdf 2020] and [https://kskedlaya.org/putnam-archive/2019.pdf 2019]. <br />
<br />
We plan to start with algebraic problems such as 2019 A1, A2, B1, B3, 2020 A1, A2, B1. Then continue to the analytic ones such as 2019 A3, A4, B2, 2020 A3. <br />
<br />
|-<br />
|Meeting September 29th, 2021<br />
Botong Wang <br />
<br />
<br />
|Continue the two sets of Putnam problems from last time. <br />
<br />
|-<br />
|Meeting October 6th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Polynomials. We'll look at the [[Media:Putnam100621-Polynomials.pdf| following problems]] (the last few problems are quite hard, and we probably won't get to them during the meeting).<br />
<br />
|-<br />
|Meeting October 13th, 2021<br />
Dima Arinkin<br />
<br />
<br />
|Continuing with the problems from last time. If you have the time, please look at the problems in advance, and then if you have ideas or questions, we would talk about it at the start. <br />
<br />
|-<br />
|Meeting October 20th, 2021<br />
Tatyana<br />
<br />
| We are going to discuss number theory problems. The plan is to look on some of the [[Media:PutClub F21 nt.pdf| following problems]] (we probably will not cover them all)<br />
<br />
<br />
|-<br />
|Meeting October 27th, 2021<br />
Tatyana<br />
<br />
|We will continue to discuss some number theory problems from the list<br />
<br />
|-<br />
|Meeting November 3rd, 2021<br />
Botong<br />
<br />
|We are going to discuss [[Media:Putnam inequalities 2021.pdf| Inequalities!]]<br />
<br />
|-<br />
|Meeting November 10th, 2021<br />
Botong<br />
<br />
|We continue the discussion of inequalities<br />
<br />
|-<br />
|Meeting November 17th, 2021<br />
Mihaela Ifrim<br />
<br />
|We started discussing [[Media:Putnam 11.24.2021.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting November 24th, 2021<br />
<br />
<br />
|Thanksgiving break<br />
<br />
|<br />
<br />
|-<br />
|Meeting December 1st, 2021<br />
Mihaela Ifrim<br />
<br />
|Working in the extra problems added to the Nov 17th pdf. Solutions to all the problems: [[Media:Putnam 11.22.2021 Sols.pdf| Various problems from past competitions]]<br />
<br />
|-<br />
|Meeting December 8th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the actual Putnam problems. Covered half of them.<br />
<br />
<br />
<br />
|-<br />
|Meeting December 15th, 2021<br />
Mihaela Ifrim<br />
<br />
|Worked on the remaining problems; we still have some left: A6 and B5. See you all after the Winter break!<br />
<br />
<br />
<br />
|}<br />
</center><br />
<br />
<br />
<br />
<br />
==Spring 2021==<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE SPRING 2021 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
The Putnam Exam, offered by the Mathematical Association of America, is the premier American math competition for undergraduate students. In a regular year is given on the first Saturday in December. The exam consists of 12 problems, 6 in the 3 hour morning session and 6 in the 3-hour afternoon session. Each problem is worth 10 points, so the maximum score is 120. National winners usually get around 100 points. The median score is generally around 0-2 points. This is a difficult exam with many interesting and fun problems.<br />
<br />
Due to the coronavirus crisis, '''the 81st Putnam Competition''', originally scheduled for Fall 2020, has been postponed until Feb. 20, 2021. The competition was in an '''unofficial mode''', with no proctors, no prizes, no awards, and no national recognition of high-scoring individuals or teams. The solution papers are uploaded by participants for grading. Scores will be reported back privately to the individual participants and the local supervisor of each institution will receive a report of the scores of the students for that institution. <br />
<br />
'''We will not continue our Putnam club meetings after March 24. See you all in the fall!<br />
'''<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting Feb 10, 2021<br />
Botong Wang<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Feb 10, 2021 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting: https://uwmadison.zoom.us/meeting/register/tJMrd-yhpjstHt34UK8YJ9_mZJ7NT_G3NLcM After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
The first two meetings will be presented by Botong. We will look at some of the most recent Putnam exams to help you prepare for the coming one. <br />
<br />
On Feb 10, we will go over some of the [https://www.maa.org/sites/default/files/pdf/Putnam/2019/2019PutnamProblems.pdf 2019 Putnam problems]. <br />
<br />
|-<br />
|Meeting Feb 17, 2021<br />
Botong Wang <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will continue to discuss problems in the 2019 Putnam competition. We will also look at some of the [https://kskedlaya.org/putnam-archive/2018.pdf 2018 Putnam problems]. </span> <br />
<br />
<br />
|-<br />
|Meeting Feb 24, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We will look at some of the problems from [https://kskedlaya.org/putnam-archive/2020.pdf this year's Putnam] (which took place last weekend). </span> <br />
<br />
|-<br />
|Meeting Mar 3, 2021<br />
Dima Arinkin<br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">Let's keep looking at the [https://kskedlaya.org/putnam-archive/2020.pdf Putnam problems] - some interesting ones left!</span> <br />
<br />
|-<br />
|Meeting Mar 10 and Mar 17, 2021<br />
Botong Wang<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will discuss several apects of combinatorics: graphs, set theory and geometric combinatorics. The worksheet is [[Media:Putnam Combinatorics 2021.pdf| here]].</span><br />
|<br />
<br />
|-<br />
|Meeting Mar 24, 2021<br />
Mihaela Ifrim<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">This week we will go over problems in linear algebra and analysis. The worksheet is [[Media:Putnam-Problems and Theory form March 23 2021.pdf| here]].</span><br />
|}<br />
<br />
<br />
<br />
==Fall 2020==<br />
<br />
<br />
<span style="color:Indigo"><font size="5"> <div style="text-align: center;">WELCOME TO THE FALL 2020 PUTNAM CLUB!</div></font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson"><font size="3">Organizers: Dima Arinkin, Mihaela Ifrim, Tatiana Shcherbyna, Botong Wang </font></span><br />
<br />
<br />
<div style="text-align: center;"><span style="color:crimson">However, this year things are a bit unusual. The 2020 Putnam competition is postponed until February 20, 2021. It is not determined yet whether the competition will be in person or online yet.Here is the original statement on the official webpage of the contest:</span> </div><br />
<br />
''Due to the coronavirus crisis, most students in the US and Canada are unable to return to campuses this fall. Therefore, the 81st Putnam Competition, originally scheduled for Fall 2020, will be postponed until February 20, 2021. If most students can return to campuses in the spring, the competition on that date can go forward in much the same form as in previous years. On the other hand, if most students are unable to return to campuses in the spring, the competition on that date will proceed in an unofficial mode, with no proctors, no prizes, no awards, but with solution papers submitted for grading by participants themselves and scores reported back privately to the individual participants.<br />
<br />
''<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;">[http://kskedlaya.org/putnam-archive/ <font size="3">Old exams and more information on the Putnam competition.</font>]</div></div><br />
<br />
<br />
The UW is also participating in the Virginia Tech Regional Mathematics Contest. This is an individual competition with seven problems in 2.5 hours. Many schools use it as a kind of rehearsal for the Putnam. You can find more information [http://intranet.math.vt.edu/people/plinnell/Vtregional/ <span style="color:crimson"> over here.</div>] <br />
<br />
<div style="text-align: center;"><font size="3">'''We will have online meetings every Wednesday 5:00-6:30PM. ''' </font></div><br />
<br />
<br />
<div style="text-align: center;"><div style="background-color:pink;"> <font size="3">The first meeting of this semester will happen on the 16th of September 2020! Please let all your colleagues know that we are continuing the Putnam Club and we are enthusiastic and hopeful we will keep you all engaged throughout the semester!</font> </div></div><br />
<br />
<br />
{| class="wikitable" style="color:red; background-color:#ffffcc;" cellpadding="50"<br />
|Meeting 16 SEPT 2020<br />
Mihaela Ifrim<br />
|ZOOM MEETING: Hi there, You are invited to a Zoom meeting. <br />
When: Sep 16, 2020 05:00 PM Central Time (US and Canada) <br />
<br />
Register in advance for this meeting:<br />
https://uwmadison.zoom.us/meeting/register/tJApcumhrz4pEtJRe_o0WTGM26u2zTM8T6J5 After registering, you will receive a confirmation email containing information about joining the meeting.<br />
<br />
You will meet us all at some point in time:) First two meetings will be presented by Mihaela. We will each teach two consecutive meetings. <br />
<br />
<span style="color:blue">UPDATE (09/17/2020): e met and all the documents (problems discussed and solutions given by you in class, are now shared with you via onedrive (app related to your outlook wisc account!)). I have also sent to you an invitation to use the witheboard attached to the same wisc account! But, do not feel discouraged in case you want to join later! You are always welcomed! </span><br />
<br />
<span style="color:green"> Please check out the following book: '''Putnam and Beyond'''! We will use it throughout the meetings!</span><br />
<br />
The first list of problems is posted! Please email me if you want access to it! [[File:Putnam_Problem_Set_1.pdf ]]<br />
<br />
<br />
|-<br />
|Meeting 23 SEPT 2020<br />
Mihaela Ifrim <br />
<br />
<br />
| Zoom: Please join using the above link!<br />
<span style="color:Indigo">We discussed the problems given in the Putnam_Problem_Set_1 and their solutions are now posted on the shared folder.<br />
In addition I have also gave you the following problems to think at. [[File:Putnam_September_23_2020.pdf]]</span> <br />
<br />
<br />
<br />
<br />
|-<br />
|Meeting 30 SEPT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please consider joining ! <br />
<span style="color:Indigo">The next meeting will cover NUMBER THEORY! Please see the attached list of problems!! Enjoy!!! [[File:Putnam_nt1(1).pdf ]]</span><br />
<br />
<br />
<br />
|-<br />
|Meeting 7 OCT 2020<br />
Tatyana Shcherbyna <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam_nt2.pdf]] If you have solutions for the previous proposed set of problems, please email them so that we can compile a set of solutions. We will post them in our onedrive folder. If you are new, please email us and we will give access to it!<br />
|-<br />
<br />
-<br />
|Meeting 14 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! Here is the list of problems for the next meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] A more detailed list is posted on onedrive! <br />
|-<br />
<br />
-<br />
|Meeting 21 OCT 2020<br />
Mihaela Ifrim <br />
<br />
| ZOOM: Please join! We worked out some of the problem proposed on the previous meeting!!! [[File:Putnam-Problems-and-Theory-form-Oct-14th-2020-short.pdf ]] Some solutions will be posted on onedrive! Reach out to us if you would like access to the solutions and you did not register yet! <br />
|-<br />
-<br />
|Meeting 28 OCT 2020<br />
Tatyana Shcherbina <br />
<br />
| ZOOM: Please join! The next two meeting will cover '''Polynomials'''! Please see the attached list of problems!! Enjoy!!! [[File: putnam_pol1.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the theory discussed on Oct 28 and hints to the problems [[File: putnam_pol1_hints.pdf ]] and [[File: polynomials_theory.pdf ]] <br />
|-<br />
<br />
<br />
<br />
|Meeting 4 Nov 2020<br />
Tatyana Shcherbina <br />
<br />
| Here are the solutions of Polynomials problems [[File: putnam_Oct28_sol.pdf ]] <br />
|-<br />
<br />
<br />
|Meeting 11 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''Linear algebra'''. Here are the [[Media:Linear algebra 2020.pdf| problems]] I plan to discuss, and here is a short [http://math.northwestern.edu/putnam/filom/Linear_and_Abstract_Algebra.pdf summary] (from NWU) of some common linear algebra techniques for math contests.<br />
|-<br />
<br />
|Meeting 18 Nov 2020<br />
Dima Arinkin <br />
<br />
| On ZOOM (the link is above). Continuing with the linear algebra: here are the [[Media:Linear algebra 2 2020.pdf| problems]] (including some left-overs from the last time). <br />
|-<br />
<br />
|Meeting 2 Dec 2020<br />
Botong Wang <br />
<br />
| On ZOOM (the link is above). The topic for the next two meetings is '''limits of sequences''' (sections 3.1.3, 3.1.4, 3.1.5 in Putnam and Beyond). We will go over some basic theorems and discuss how to apply them. Here is the [[Media:Putnam limits.pdf| worksheet]].<br />
|-<br />
|}<br />
<br />
<br />
----<br />
<br />
==Spring 2020==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. <br />
<br />
The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 5: [[Media:Putnam Binomial2020.pdf| Binomial coefficients and generating functions]] [[Media:Putnam Binomial2020 answer.pdf| (Answers and hints)]] Botong<br />
* February 19: [[Media:Putnam Number theory2020.pdf| Number theory]] [[Media:Putnam Number2020.pdf| (Answers and hints)]] Botong<br />
* March 4 and 11: [[Media:Inequalities.pdf| Inequalities]] ( Note comming up!) Kim<br />
<br />
==Fall 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 25th of September in Van Vleck hall, room B139.'''<br />
<br />
We will continue using the [http://piazza.com/wisc/fall2018/putnam2018/ Piazza page] from last semester for discussions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* September 25: [[Media:Putnam problems 2017+2018.pdf| Introductory meeting]] Botong<br />
* October 2: [[Putnam.pdf | Integral inequalities]] Mihaela<br />
* October 9: [[Putnam.pdf | More about Integral inequalities]] (I will post notes on Wednesday morning and we will discuss more in class!) Mihaela<br />
* October 16: [[ODE.pdf | ODE of the first order]] Chanwoo<br />
* November 6: [[Media:Numbers.pdf| Number theory]] Dima<br />
* November 13: ??<br />
* November 20: [[Geometry.pdf | Geometry]] ( Note comming up!) Mihaela<br />
* November 27: [[No meeting! Thanksgiving! ]]<br />
* December 4: Last meeting of the semester! Please come and bring your friends too!! It will be fun! Mihaela<br />
<br />
<br />
<br />
<br />
==Spring 2019==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other Olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. The first meeting will be on the 6th of February in Van Vleck hall, room B139.<br />
<br />
<br />
<br />
'''! Important announcement:''' We will begin preparing you for the Putnam exam earlier this year. The material covered will be presented gradually. More details will be explained to you during your first meeting of this semester (Feb 6th). We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
* February 6: [[Media:Putnam Basics 2019.pdf| The basics]] by Botong<br />
* February 13: Botong<br />
* February 20: Alex [[Media:Ordered Sets.pdf| Ordered Sets]]<br />
* March 6th: Mihaela [[Media:Putnam.pdf| Algebra]]<br />
* March 13: Mihaela<br />
* March 27: Botong [[Media:Matrix.pdf| Matrices]]<br />
<br />
If this material is completely new to you then read through the definitions in the first section and try the interspersed exercises which are direct applications of the definitions. If you are familiar with the basic material then review the problem solving strategies and the example problems which directly utilize the techniques. Finally, if you are a veteran, go ahead and jump right to the exercises!<br />
* February 27: Alex: Review results from 2/20. Bring written solutions and/or be prepared to present your <br />
* March 6th: Mihaela<br />
* March 13: Mihaela<br />
etc.<br />
<br />
==Fall 2018==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139. '''The first meeting will be on the 26th of September in Van Vleck hall, room B139.'''<br />
<br />
'''! Important announcement:''' We put together a Piazza account that will help the participants to discuss and collaborate with their pairs. Here is the link you need to access in order to register for this "class": piazza.com/wisc/fall2018/putnam2018 . Our intervention on Piazza will be minimal (some of the instructors will, from time to time, visit the piazza questions and provide some help). Also, based on your requests, we have decided to structure our meetings in a way that will provide more insight on methods and certain tricks that are very often used in this type of math competitions. The book we will mainly use as a guide in preparing our meetings is: "Putnam and Beyond" by Razvan Gelca and Titu Andreescu. <br />
<br />
<br />
<br />
* September 26: topic [[Media:Putnam 26 sept 2018.pdf| Introductory meeting]] by Mihaela Ifrim. We covered only the first 3 problems. I encourage you to work out all the problems!<br />
<br />
* October 3: [[Media:Putnam Oct 3 2018.pdf| Linear Algebra]] by George Craciun.<br />
<br />
* October 10: [[Media:Putnam polynomials 2018.pdf| Polynomials]] by Botong Wang.<br />
<br />
* October 17: [[Media:SeqPut18.pdf| Sequences]] by Alex Hanhart.<br />
<br />
* October 24: [[Media:Putnam Oct 24th 2018.pdf| Convergence and Continuity]] by Mihaela Ifrim.<br />
<br />
* October 27: Virginia Tech Math Contest: 9-11:30am in VV B115.<br />
<br />
* October 31: [[Media:Putnam Oct 31 2018.pdf| Geometry: cartesian coordinates, complex coordinates, circles and conics]] by George Craciun.<br />
<br />
* November 7: [[Media:Putnam Combinatorics 2018.pdf| Combinatorics: Set theory and geometric combinatorics]] by Botong Wang.<br />
<br />
* November 14: [[Media:Group.pdf| Techniques from Group Theory]] by Alex Hanhart.<br />
<br />
* November 21: '''No meeting''': Happy Thanksgiving!<br />
<br />
* November 28: [[Media:Putnam November 28 2018.pdf| Number Theory]] by Mihaela Ifrim.<br />
<br />
* December 1: Putnam Competition! Starts at 9am!!!! '''The competition will take place December 1st 2018 (Saturday December 1st). The competition is administered in two sessions (A and B) on the same day, December 1st! Session A will start at 9 am and it will end at 12pm, and Session B will start at 2pm and it will end at 5pm. You should arrive at least 10 minutes prior to each session. You should bring your own pencils and pens (blue or black ink are permitted). Number 2 pencils with erasers will be needed to complete the identification forms. Erasers are also permitted, but nothing else will not be allowed in the exam room. I plan on bringing 20 such no 2 pencils. The exam room is B239 which is a class room located in Van Vleck Hall, at the level B2. Thank you all for participating and see you all there! If you have friends that would like to take the exam please encourage them to do so.'''<br />
<br />
==Spring 2018==<br />
<br />
The Putnam Club does not meet in the spring, but we had the fourth annual UW [[Undergraduate Math Competition]] on '''April 24th''', 2018, 5:30-8pm in VV B239.<br />
<br />
==Fall 2017==<br />
<br />
The Putnam Club will help you prepare for the exam by practicing on problems from previous years and other olympiad-style problems. The meeting time is 5pm on Wednesdays in VV B139.<br />
<br />
* September 20: [[Media:Putnam092017.pdf| Introductory meeting]] by D.Arinkin<br />
* September 27: [[Media:Putnam092717.pdf| Equations with functions as unknowns]] by M.Ifrim (by request: here is [[Media:Putnam092717sol6.pdf| a solution to problem 6]]; problem 7 is problem B5 of 2016 Putnam exam; you can see the solution [http://kskedlaya.org/putnam-archive/2016s.pdf here]).<br />
* October 4: [[Media:Putnam100417.pdf| Inequalities]] by G.Craciun.<br />
* October 11: [[Media:Putnam101117.pdf| Polynomials]] by D.Arinkin.<br />
* October 18: [[Media:Putnam1(2)..pdf| Equations]] by M. Ifrim<br />
* October 21: Virginia Tech Math Contest: 9-11:30am in VV B203.<br />
* October 25: Review of this year's [[Media:VTRMC2017.pdf| Virginia Tech Contest]] by G.Craciun.<br />
* November 1: [[Media:Putnam110117.pdf| Functions and calculus]] by D.Arinkin.<br />
* November 8: [[Media:Putnam1.pdf| Past Competitions]] by M.Ifrim<br />
* November 15: [[Media:Putnam111517.pdf| Recurrences]] by G.Craciun.<br />
* November 22: '''No meeting''': Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112917.pdf| Complex numbers]] by D.Arinkin.<br />
* December 2: '''Putnam Exam''' in VVB115. Morning session: 9-12pm; Afternoon session: 2-5pm.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the third annual UW [[Undergraduate Math Competition]] on April 19th, 2017.<br />
<br />
==Fall 2016==<br />
<br />
* September 20: [[Media:Putnam092016.pdf| Introductory meeting]]<br />
* September 27: [[Media:Putnam092716.pdf| Calculus and analysis]]<br />
* October 4: [[Media:Putnam100416.pdf| Generating functions]] (by Vlad Matei)<br />
* October 11: [[Media:UWUMC2016.pdf| Review of last year's UW Math competition]]<br />
* October 18: [[Media:Putnam101816.pdf| Functional equations]]<br />
* October 22: Virginia Tech Math Contest<br />
* October 25: Review of this year's [[Media:Vtrmc16.pdf| VT contest]]<br />
* November 1: [[Media:Putnam110116.pdf| Matrices]] (by Vlad Matei)<br />
* November 15: [[Media:Putnam111516.pdf| Two algebra problems]]<br />
* November 22: No meeting: Happy Thanksgiving!<br />
* November 29: [[Media:Putnam112916.pdf| Assorted problems]]<br />
* December 3: Putnam Exam: Morning session: 9am-noon, Afternoon session: 2-5pm in VV B135.<br />
<br />
==Spring 2016==<br />
<br />
The Putnam Club does not meet in the spring, but we had the second annual UW [[Undergraduate Math Competition]] on April 12th, 2016.<br />
<br />
==Fall 2015==<br />
. <br />
* September 23rd: [[Media:Putnam092315.pdf| Introductory meeting]]<br />
* September 30th: [[Media:Putnam093015.pdf| Pigeonhole principle]]<br />
* October 7th: Review of [[Media:UWUMC2015.pdf| 2015 UW math competition]]<br />
* October 14th: [[Media:Putnam101415.pdf| Matrices and determinants]]<br />
* October 21st: [[Media:Putnam102115.pdf| Virginia Tech practice]]<br />
* October 24th: Virginia Tech Regional Mathematics Contest: 9-11:30 am<br />
* October 28th: Review of the 2015 Virginia Tech contest.<br />
* November 4th: [[Media:PutnamProblemsOct12.pdf| Polynomials]]<br />
* November 11th: [[Media:PutnamProblemsNov11.pdf| Assorted problems]]<br />
* November 18th: [[Media:PutnamProblemsNov18.pdf| Assorted problems]]<br />
* No meeting on November 25th<br />
* December 2nd: TBA<br />
* December 5th: Putnam competition: Morning session: 9am-12pm, afternoon session: 2-5pm in VV B115.<br />
<br />
==Spring 2015==<br />
<br />
The Putnam Club does not meet in the spring, but we had our first UW [[Undergraduate Math Competition]]!<br />
<br />
==Fall 2014==<br />
<br />
* September 17: [[Media:Putnam091714.pdf| Introductory meeting]]<br />
* September 22: [[Media:Putnam092214.pdf| Coloring and pigeonhole principle]]<br />
* October 1st: Went through HW problems from last time<br />
* October 8th: [[Media:Putnam100814.pdf| Number theory]]<br />
* October 15th: [[Media:Putnam101514.pdf| Games]]<br />
* October 22nd: [[Media:VTRMC13.pdf| Problems from last year's Virginia Tech contest]]<br />
* October 25th: Virginia Tech Regional Mathematics Contest<br />
* October 29th: Review of this year's Virginia Tech contest<br />
* November 5th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/06-inequalities.pdf Inequalities] and [http://www.math.cmu.edu/~lohp/docs/math/2014-295/05-functional.pdf functional equations]<br />
* November 12th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/02-polynomials.pdf Polynomials]<br />
* November 19th: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/10-combinatorics.pdf Combinatorics]<br />
* December 3rd: [http://www.math.cmu.edu/~lohp/docs/math/2014-295/08-recursions.pdf Recursions]<br />
* December 6th: Putnam competition: Morning session: 9am-12pm, Afternoon session: 2pm-5pm in Van Vleck B119<br />
* December 10th: Review of [http://www.artofproblemsolving.com/Forum/resources/files/undergraduate_competitions/Undergraduate_Competitions-Putnam-2014-23 this year's Putnam]<br />
<br />
==Fall 2013==<br />
<br />
<br />
* September 11: [[Media:Putnam091113.pdf| Introductory Meeting]]<br />
* September 18: [[Media:Putnam091813.pdf| Assorted Problems]] (by Yihe Dong)<br />
* September 25: [[Media:Putnam092513.pdf| Combinatorics]]<br />
* October 2: [[Media:Putnam100213.pdf| Matrices and Linear Algebra]]<br />
* October 9: [[Media:Putnam100913.pdf| Number Theory]]<br />
* October 16: [[Media:Putnam101613.pdf| Functions and Calculus]]<br />
* October 23: [[Media:Putnam102313.pdf| Polynomials]]<br />
* October 26: Virginia Tech Regional Mathematics Contest<br />
* October 30: [[Media:VTRMC13.pdf| Problems from this year's Virginia Tech contest]]<br />
* November 6: [[Media:Putnam110413.pdf| Games]]<br />
* November 13: [[Media:Putnam111113.pdf| Pigeonhole Principle]]<br />
* November 20: [[Media:Putnam112013.pdf| Extreme Principle]]<br />
* November 27: No meeting (Thanksgiving)<br />
* December 4: TBA<br />
* December 7: Putnam competition Morning session: 9am-12pm, afternoon session: 2-5pm in VV B239.<br />
<br />
==Fall 2012==<br />
<br />
* September 11: Introduction [[Media:Putnam2012IntroProblems.pdf| Problems]]<br />
* September 18: Some Basic Techniques [[Media:Putnam2012Week1Problems.pdf| Problems]]<br />
* September 25: Polynomials and Algebra [[Media:Putnam2012Week2Problems.pdf| Problems]]<br />
* October 2: Number Theory [[Media:Putnam2012Week3Problems.pdf| Problems]]<br />
* October 9: Calculus [[Media:Putnam2012Week4Problems.pdf| Problems]]<br />
* October 16: Games and Algorithms [[Media:Putnam2012Week5Problems.pdf| Problems]]<br />
* October 23: Combinatorics [[Media:Putnam2012Week6Problems.pdf| Problems]]<br />
* October 30: Probability [[Media:Putnam2012Week7Problems.pdf| Problems]]<br />
* November 6: Linear Algebra [[Media:Putnam2012Week8Problems.pdf| Problems]]<br />
* November 13: Grab Bag [[Media:Putnam2012Week9Problems.pdf| Problems]]<br />
* November 27: Grab Bag 2 [[Media:Putnam2012Week10Problems.pdf| Problems]]<br />
<br />
==Fall 2011==<br />
<br />
* September 21: Pigeonhole Principle (Brian Rice) [[Media:PutnamProblemsSept21.pdf| Problems]]<br />
* September 28: Introduction to Counting (Brian Rice) [[Media:PutnamProblemsSept28.pdf| Problems]]<br />
* October 5: Elementary Number Theory (Brian Rice) [[Media:PutnamProblemsOct5.pdf| Problems]], [[Media:PutnamProblemsOct5Hard.pdf| Problems (Hardcore)]]<br />
* October 12: Polynomials (Brian Rice) [[Media:PutnamProblemsOct12.pdf| Problems]], [[Media:PutnamProblemsOct12Hard.pdf| Problems (Hardcore)]]<br />
* October 19: A Grab Bag of Discrete Math (Brian Rice) [[Media:PutnamProblemsOct19.pdf| Problems]]<br />
* October 26: Calculus, Week 1 (Brian Rice) [[Media:PutnamProblemsOct26.pdf| Problems]]<br />
* November 2: Calculus, Week 2 (Brian Rice) [[Media:PutnamProblemsNov2.pdf| Problems]]<br />
* November 9: Linear and Abstract Algebra (Brian Rice) [[Media:PutnamProblemsNov9.pdf| Problems]]<br />
* November 16: Mock Putnam [[Media:MockPutnamProblems.pdf| Problems]], [[Media:MockPutnamSolutions.pdf| Solutions]]</div>Apisahttps://wiki.math.wisc.edu/index.php?title=File:Putnam_Club_Linear_Algebra_Techniques.pdf&diff=23971File:Putnam Club Linear Algebra Techniques.pdf2022-11-01T03:53:50Z<p>Apisa: </p>
<hr />
<div></div>Apisahttps://wiki.math.wisc.edu/index.php?title=Dynamics_Seminar_2022-2023&diff=23823Dynamics Seminar 2022-20232022-10-07T01:54:23Z<p>Apisa: /* Spring 2023 */</p>
<hr />
<div>The [[Dynamics]] seminar meets in room '''B329 of Van Vleck Hall''' on '''Mondays''' from '''2:30pm - 3:20pm'''. To sign up for the mailing list send an email from your wisc.edu address to dynamics+join@g-groups.wisc.edu. For more information, contact Paul Apisa, Marissa Loving, Caglar Uyanik, or Chenxi Wu. Contact Caglar Uyanik with your wisc email to get the zoom link for virtual talks. <br />
<br />
<br />
<br />
== Fall 2022 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
<br />
|-<br />
|September 12<br />
|[https://math.ou.edu/~jing/ Jing Tao] (OU)<br />
|[[#Jing Tao|Genericity of pseudo-Anosov maps]]<br />
|Dymarz and Uyanik<br />
|-<br />
|September 19<br />
|[https://math.temple.edu/~tug67058/ Rebekah Palmer] (Temple)(virtual)<br />
|[[#Rebekah Palmer|Totally geodesic surfaces in knot complements]]<br />
|VIRTUAL<br />
|-<br />
|September 26<br />
|[https://sites.google.com/view/beibei-liu/ Beibei Liu] (MIT)<br />
|[[#Beibei Liu|The critical exponent: old and new]]<br />
| Dymarz<br />
|-<br />
|October 3<br />
|Grace Work (UW-Madison)<br />
|[[#Grace Work |Discretely shrinking targets in moduli space]]<br />
|local<br />
|-<br />
|October 10<br />
|[https://mutanguha.com/ Jean Pierre Mutanguha] (Princeton)<br />
|[[#Jean Pierre Mutanguha| Canonical forms for free group automorphisms]]<br />
|Uyanik<br />
|-<br />
|October 17<br />
|[https://sites.google.com/ucsd.edu/ans032/ Anthony Sanchez] (UCSD)<br />
|[[#Anthony Sanchez | Kontsevich-Zorich monodromy groups of translation covers of some platonic solids]]<br />
|Uyanik<br />
|-<br />
|October 24<br />
|[https://you.stonybrook.edu/aerchenko/ Alena Erchenko] (U Chicago)<br />
|[[#Alena Erchenko| ''TBA'']]<br />
|Uyanik and Work<br />
|-<br />
|October 31<br />
|[https://sites.google.com/view/zhufeng-math/home Feng Zhu] (UW Madison)<br />
|[[#Feng Zhu| ''TBA'']]<br />
|local<br />
|-<br />
|November 7<br />
|[https://sites.google.com/bc.edu/ethan-farber/about-me?authuser=0/ Ethan Farber] (BC)<br />
|[[#Ethan Farber| ''TBA'']]<br />
|Loving<br />
|-<br />
|November 14<br />
|[https://www.math.montana.edu/geyer/ Lukas Geyer] (Montana) <br />
|[[#Lukas Geyer| ''TBA'']]<br />
|Burkart<br />
|-<br />
|November 21<br />
|[http://www.hbaik.org/ Harry Hyungryul Baik] (KAIST)<br />
|[[#Harry Baik| ''TBA'']]<br />
|Wu<br />
|-<br />
|November 28<br />
|[https://sites.google.com/view/lovingmath/home Marissa Loving] (UW Madison)<br />
|[[#Marissa Loving| ''TBA'']]<br />
|local<br />
|-<br />
|December 5<br />
|[https://mmontee.people.sites.carleton.edu MurphyKate Montee] (Carleton)<br />
|[[#MurphyKate Montee | ''TBA'']]<br />
|Dymarz<br />
|-<br />
|December 12<br />
|[https://scholar.harvard.edu/tinatorkaman/home Tina Torkaman] (Harvard)<br />
|[[#Tina Torkaman| ''TBA'']]<br />
|Uyanik<br />
|}<br />
<br />
== Fall Abstracts ==<br />
<br />
===Jing Tao===<br />
By Nielsen-Thurston classification, every homeomorphism of a surface is isotopic to one of three types: finite order, reducible, or pseudo-Anosov. While there are these three types, it is natural to wonder which type is more prevalent. In any reasonable way to sample matrices in SL(2,Z), irreducible matrices should be generic. One expects something similar for pseudo-Anosov maps. In joint work with Erlandsson and Souto, we define a notion of genericity and show that pseudo-Anosov maps are indeed generic. More precisely, we consider several "norms" on the mapping class group of the surface, and show that the proportion of pseudo-Anosov maps in a ball of radius r tends to 1 as r tends to infinity. The norms can be thought of as the natural analogues of matrix norms on SL(2,Z).<br />
<br />
===Rebekah Palmer===<br />
Studying totally geodesic surfaces has been essential in understanding the geometry and topology of hyperbolic 3-manifolds. Recently, Bader--Fisher--Miller--Stover showed that containing infinitely many such surfaces compels a manifold to be arithmetic. We are hence interested in counting totally geodesic surfaces in hyperbolic 3-manifolds in the finite (possibly zero) case. In joint work with Khánh Lê, we expand an obstruction, due to Calegari, to the existence of these surfaces. On the flipside, we prove the uniqueness of known totally geodesic surfaces by considering their behavior in the universal cover. This talk will explore this progress for both the uniqueness and the absence.<br />
<br />
===Beibei Liu===<br />
The critical exponent is an important numerical invariant of discrete groups acting on negatively curved Hadamard manifolds, Gromov hyperbolic spaces, and higher-rank symmetric spaces. In this talk, I will focus on discrete groups acting on hyperbolic spaces (i.e., Kleinian groups), which is a family of important examples of these three types of spaces. In particular, I will review the classical result relating the critical exponent to the Hausdorff dimension using the Patterson-Sullivan theory and introduce new results about Kleinian groups with small or large critical exponents. <br />
<br />
===Grace Work===<br />
The shrinking target problem characterizes when there is a full measure set of points that hit a decreasing family of target sets under a given flow. This question is closely related to the Borel Cantilli lemma and also gives rise to logarithm laws. We will examine the discrete shrinking target problem in a general and then more specifically in the setting of Teichmuller flow on the moduli space of unit-area quadratic differentials.<br />
<br />
===Jean Pierre Mutanguha===<br />
The Nielsen–Thurston theory of surface homeomorphisms can be thought of as a surface analogue to the Jordan Canonical Form. I will discuss my progress in developing a similar canonical form for free group automorphisms. (Un)Fortunately, free group automorphisms can have arbitrarily complicated behaviour. This is a significant barrier to translating arguments that worked for surfaces into the free group setting; nevertheless, the overall ideas/strategies do translate!<br />
<br />
===Anthony Sanchez===<br />
Platonic solids have been studied for thousands of years. By unfolding a platonic solid we can associate to it a translation surface. Interesting information about the underlying platonic solid can be discovered in the cover where more (dynamical and geometric) structure is present. The translation covers we consider have a large group of symmetries that leave the global composition of the surface unchanged. However, the local structure of paths on the surface is often sensitive to these symmetries. The Kontsevich-Zorich mondromy group keeps track of this sensitivity. <br />
<br />
In joint work with R. Gutiérrez-Romo and D. Lee, we study the monodromy groups of translation covers of some platonic solids and show that the Zariski closure is a power of SL(2,R). We prove our results by finding generators for the monodromy groups, using a theorem of Matheus–Yoccoz–Zmiaikou that provides constraints on the Zariski closure of the groups (to obtain an "upper bound"), and analyzing the dimension of the Lie algebra of the Zariski closure of the group (to obtain a "lower bound").<br />
<br />
===Alena Erchenko===<br />
<br />
===Feng Zhu===<br />
<br />
===Ethan Farber===<br />
<br />
===Lukas Geyer===<br />
<br />
===Harry Baik ===<br />
<br />
===Marissa Loving===<br />
<br />
===MurphyKate Montee===<br />
<br />
===Tina Torkaman===<br />
<br />
<br />
==Spring 2023==<br />
<br />
{| cellpadding="8"<br />
! align="left" |date<br />
! align="left" |speaker<br />
! align="left" |title<br />
! align="left" |host(s)<br />
|-<br />
|January 30<br />
|Pierre-Louis Blayac (Michigan)<br />
|[[#Pierre-Louis Blayac| ''TBA'']]<br />
|Zhu and Zimmer<br />
|-<br />
|February 6<br />
|[http://www-personal.umich.edu/~kbutt/index.html Karen Butt] (Michigan)<br />
|[[#Karen Butt| ''TBA'']]<br />
|Zimmer<br />
|-<br />
|March 27<br />
|[https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis)<br />
|[[#Carolyn Abbott| ''TBA'']]<br />
|Dymarz and Uyanik<br />
|-<br />
|April 3<br />
|[https://sites.google.com/view/sfairchild/home Samantha Fairchild] (Osnabrück)<br />
|TBA<br />
|Apisa<br />
|-<br />
|April 10<br />
|[https://www.math.utah.edu/~chaika/ Jon Chaika] (Utah)<br />
|[[#Jon Chaika| ''TBA'']]<br />
|Apisa and Uyanik<br />
|-<br />
|April 24<br />
|[https://www.patelp.com Priyam Patel] (Utah)<br />
|[[#Priyam Patel| TBA]]<br />
|Loving and Uyanik<br />
|}<br />
<br />
==Spring Abstracts==<br />
<br />
===Pierre-Louis Blayac===<br />
<br />
===Karen Butt===<br />
<br />
===Carolyn Abbott===<br />
'''<big>Samantha Fairchild</big>'''<br />
<br />
===Jon Chaika===<br />
<br />
===Priyam Patel ===<br />
<br />
== Archive of past Dynamics seminars==<br />
<br />
2021-2022 [[Dynamics_Seminar_2021-2022]]<br />
<br />
2020-2021 [[Dynamics_Seminar_2020-2021]]</div>Apisa