AMS Student Chapter Seminar: Difference between revisions

From UW-Math Wiki
Jump to navigation Jump to search
VisualWikitext
No edit summary
 
(315 intermediate revisions by 31 users not shown)
Line 1: Line 1:
The AMS Student Chapter Seminar is an informal, graduate student-run seminar on a wide range of mathematical topics. Pastries (usually donuts) will be provided.
The AMS Student Chapter Seminar (aka Donut Seminar) is an informal, graduate student seminar on a wide range of mathematical topics. The goal of the seminar is to promote community building and give graduate students an opportunity to communicate fun, accessible math to their peers in a stress-free (but not sugar-free) environment. Pastries (usually donuts) will be provided.


* '''When:''' Wednesdays, 3:30 PM – 4:00 PM
* '''When:''' Thursdays 4:00-4:30pm
* '''Where:''' Van Vleck, 9th floor lounge
* '''Where:''' Van Vleck, 9th floor lounge (unless otherwise announced)
* '''Organizers:''' Daniel Hast, Ryan Julian, Laura Cladek, Cullen McDonald, Zachary Charles
* '''Organizers:''' Ivan Aidun, Kaiyi Huang, Ethan Schondorf


Everyone is welcome to give a talk. To sign up, please contact one of the organizers with a title and abstract. Talks are 30 minutes long and should avoid assuming significant mathematical background beyond first-year graduate courses.
Everyone is welcome to give a talk. To sign up, please contact one of the organizers with a title and abstract. Talks are 25 minutes long and should avoid assuming significant mathematical background beyond first-year graduate courses.


== Spring 2016 ==
The schedule of talks from past semesters can be found [[AMS Student Chapter Seminar, previous semesters|here]].


=== January 27, Wanlin Li ===
== Fall 2024 ==
<center>
{| cellspacing="5" cellpadding="14" border="0" style="color:black; font-size:120%"
! align="center" width="200" bgcolor="#D0D0D0" |'''Date'''
! align="center" width="200" bgcolor="#A6B658" |'''Speaker'''
! align="center" width="300" bgcolor="#BCD2EE" |'''Title'''
! align="center" width="400" bgcolor="#BCD2EE" |'''Abstract'''
|-
| bgcolor="#D0D0D0" |September 12
| bgcolor="#A6B658" |Ari Davidovsky
| bgcolor="#BCD2EE" |95% of people can't solve this!
| bgcolor="#BCD2EE" | [[File:Image.png|360px]]


Title: The Nottingham group
We will attempt to answer this question and along the way explore how algebra and geometry work together to solve problems in number theory.
|-
| bgcolor="#D0D0D0" |September 19
| bgcolor="#A6B658" |CANCELLED
| bgcolor="#BCD2EE" |NONE
| bgcolor="#BCD2EE" |NONE
|-
| bgcolor="#D0D0D0" |September 26
| bgcolor="#A6B658" |Mateo Morales
| bgcolor="#BCD2EE" |Officially petitioning the department to acquire a ping pong table.
| bgcolor="#BCD2EE" |Ever want to prove something is a free group of rank 2? Me too. One way to do this is to use a ping pong argument of how a group generated by two elements acts on a set.
I will illustrate the ping pong argument using an example of matrices, explain how it works, and explain why, kinda.


Abstract: It's the group of wild automorphisms of the local field F_q((t)). It's a finitely generated pro-p group. It's hereditarily just infinite. Every finite p-group can be embedded in it.  It's a favorite test case for conjectures concerning pro-p groups.  It's the Nottingham group! I will introduce you to this nice pro-p group which is loved by group theorists and number theorists.
Very approachable if you know what a group is but does require tons of ping pong experience.
 
|-
=== February 3, Will Cocke ===
| bgcolor="#D0D0D0" |October 3
 
| bgcolor="#A6B658" |Karthik Ravishankar
Title: Who or What is the First Order & Why Should I Care?
| bgcolor="#BCD2EE" |Incompleteness for the working mathematician
 
| bgcolor="#BCD2EE" |In this talk we'll take a look at Gödels famous incompleteness theorems and look at some of its immediate as well as interesting consequences. No background in logic is necessary!
Abstract: As noted in recent films, the First Order is very powerful. We will discuss automated theorem proving software, including what exactly that means. We will then demonstrate some theorems, including previously unknown results, whose proofs can be mined from your computer.
|-
 
| bgcolor="#D0D0D0" |October 10
=== February 10, Jason Steinberg ===
| bgcolor="#A6B658" |Elizabeth Hankins
 
| bgcolor="#BCD2EE" |Mathematical Origami and Flat-Foldability
Title: Mazur's Swindle
| bgcolor="#BCD2EE" |If you've ever unfolded a piece of origami, you might have noticed complicated symmetries in the pattern of creases left behind. What patterns of lines can and cannot be folded into origami? And why is it sometimes hard to determine?
 
|-
Abstract: If we sum the series 1-1+1-1+1-1+... in two ways, we get the nonsensical result 0=1 as follows: 0=(1-1)+(1-1)+(1-1)+...=1+(-1+1)+(-1+1)+...=1. While the argument is invalid in the context of adding infinitely many numbers together, there are other contexts throughout mathematics when it makes sense to take arbitrary infinite "sums" of objects in a way that these sums satisfy an infinite form of associativity. In such contexts, the above argument is valid. Examples of such contexts are connected sums of manifolds, disjoint unions of sets, and direct sums of modules, and in each case we can use this kind of argument to achieve nontrivial results fairly easily. Almost too easily...
| bgcolor="#D0D0D0" |October 17
 
| bgcolor="#A6B658" |CANCELLED
=== February 17, Zachary Charles ===
| bgcolor="#BCD2EE" |NONE
 
| bgcolor="#BCD2EE" |NONE
Title: #P and Me: A tale of permanent complexity
|-
 
| bgcolor="#D0D0D0" |October 24
Abstract: The permanent is the neglected younger sibling of the determinant. We will discuss the permanent, its properties, and its applications in graph theory and commutative algebra. We will then talk about computational complexity classes and why the permanent lies at a very strange place in the complexity hierarchy. If time permits, we will discuss operations with even sillier names, such as the immanant.
| bgcolor="#A6B658" |CANCELLED
 
| bgcolor="#BCD2EE" |NONE
=== February 24, Brandon Alberts ===
| bgcolor="#BCD2EE" |NONE
 
|-
Title: The Rado Graph
| bgcolor="#D0D0D0" |October 31
 
| bgcolor="#A6B658" |Jacob Wood
Abstract: A graph so unique, that a countably infinite random graph is isomorphic to the Rado Graph with probability 1. This talk will define the Rado Graph and walk through a proof of this surprising property.
| bgcolor="#BCD2EE" |What is the length of a <s>potato</s> pumpkin?
 
| bgcolor="#BCD2EE" |How many is a jack-o-lantern? What is the length of a pumpkin? These questions sound like nonsense, but they have perfectly reasonable interpretations with perfectly reasonable answers. On our journey through the haunted house with two rooms, we will encounter some scary characters like differential topology and measure theory. Do not fear; little to no experience in either subject is required.
=== March 2, Vlad Matei ===
|-
 
| bgcolor="#D0D0D0" |November 7
Title: Pythagoras numbers of fields
| bgcolor="#A6B658" |CANCELLED: DISTINGUISHED LECTURE
 
| bgcolor="#BCD2EE" |NONE
Abstract: The Pythagoras number of a field describes the structure of the set of squares in the field. The Pythagoras number p(K) of a field K is the smallest positive integer p such that every sum of squares in K is a sum of p squares.
| bgcolor="#BCD2EE" |NONE
 
|-
A pythagorean field is one with Pythagoras number 1: that is, every sum of squares is already a square.
| bgcolor="#D0D0D0" |November 14
 
| bgcolor="#A6B658" |Sapir Ben-Shahar
These fields have been studied for over a century and it all started with David Hilbert and his famous 17th problem and whether or not positive polynomial function on '''R'''^n can be written as a finite sum of squares of polynomial functions.
| bgcolor="#BCD2EE" |Hexaflexagons
 
| bgcolor="#BCD2EE" |Come along for some hexaflexafun and discover the mysterious properties of hexaflexagons, the bestagons! Learn how to make and navigate through the folds of your very own paper hexaflexagon. No prior knowledge of hexagons (or hexaflexagons) is assumed.
We explore the history and various results and some unanswered questions.
|-
 
| bgcolor="#D0D0D0" |November 21
=== March 9, Micky Steinberg ===
| bgcolor="#A6B658" |Andrew Krenz
 
| bgcolor="#BCD2EE" |All concepts are database queries
Title: TBA
| bgcolor="#BCD2EE" |A celebrated result of applied category theory states that the category of small categories is equivalent to the category of database schemas. Therefore, every theorem about small categories can be interpreted as a theorem about databases.  Maybe you've heard someone repeat Mac Lane's famous slogan "all concepts are Kan extensions."  In this talk, I'll give a high-level overview of/introduction to categorical database theory (developed by David Spivak) wherein Kan extensions play the role of regular every day database queries.  No familiarity with categories or databases will be assumed.
 
|-
Abstract: TBA
| bgcolor="#D0D0D0" |November 28
 
| bgcolor="#A6B658" |THANKSGIVING
=== March 16, TBA ===
| bgcolor="#BCD2EE" |NONE
 
| bgcolor="#BCD2EE" |NONE
=== March 30, TBA ===
|-
 
| bgcolor="#D0D0D0" |December 5
=== April 6, TBA ===
| bgcolor="#A6B658" |Caroline Nunn
 
| bgcolor="#BCD2EE" |TBA
=== April 13, TBA ===
| bgcolor="#BCD2EE" |T
 
|}
=== April 20, TBA ===
</center>
 
=== April 27, TBA ===
 
=== May 4, TBA ===
 
=== May 10, TBA ===
 
== Fall 2015 ==
 
=== October 7, Eric Ramos ===
 
Title: Configuration Spaces of Graphs
 
Abstract: A configuration of n points on a graph is just a choice of n distinct points. The set of all such configurations is a topological space, and so one can study its properties. Unsurprisingly, one can determine a lot of information about this configuration space from combinatorial data of the graph. In this talk, we consider some of the most basic properties of these spaces, and discuss how they can be applied to things like robotics. Note that most of the talk will amount to drawing pictures until everyone agrees a statement is true.
 
=== October 14, Moisés Herradón ===
 
Title: The natural numbers form a field
 
Abstract: But of course, you already knew that they form a field: you just have to biject them into Q and then use the sum and product from the rational numbers. However, out of the many field structures the natural numbers can have, the one I’ll talk about is for sure the cutest. I will discuss how this field shows up in "nature" (i.e. in the games of some fellows of infinite jest) and what cute properties it has.
 
=== October 21, David Bruce ===
 
Title: Coverings, Dynamics, and Kneading Sequences
 
Abstract: Given a continuous map f:X—>X of topological spaces and a point x in X one can consider the set {x, f(x), f(f(x)), f(f(f(x))),…} i.e, the orbit of x under the map f. The study of such things even in simple cases, for example when X is the complex numbers and f is a (quadratic) polynomial, turns out to be quite complex (pun sort of intended). (It also gives rise to main source of pretty pictures mathematicians put on posters.) In this talk I want to show how the study of such orbits is related to the following question: How can one tell if a (ramified) covering of S^2 comes from a rational function? No background will be assumed and there will be pretty pictures to stare at.
 
=== October 28, Paul Tveite ===
 
Title: Gödel Incompleteness, Goodstein's Theorem, and the Hydra Game
 
Abstract: Gödel incompleteness states, roughly, that there are statements about the natural numbers that are true, but cannot be proved using just Peano Arithmetic. I will give a couple concrete examples of such statements, and prove them in higher mathematics.
 
=== November 4, Wanlin Li ===
 
Title: Expander Families, Ramanujan graphs, and Property tau
 
Abstract: Expander family is an interesting topic in graph theory. I will define it, give non-examples and talk about the ideal kind of it, i.e. Ramanujan graph. Also, I will talk about property tau of a group and how it is related to expander families. To make the talk not full of definitions, here are part of the things I'm not going to define: Graph, regular graph, Bipartite graph, Adjacency matrix of a graph and tea...
 
=== November 11, Daniel Hast ===
 
Title: Scissor groups of polyhedra and Hilbert's third problem
 
Abstract: Given two polytopes of equal measure (area, volume, etc.), can the first be cut into finitely many polytopic pieces and reassembled into the second? To investigate this question, we will introduce the notion of a "scissor group" and compute the scissor group of polygons. We will also discuss the polyhedral case and how it relates to Dehn's solution to Hilbert's third problem. If there is time, we may mention some fancier examples of scissor groups.
 
=== November 18, James Waddington ===
 
''Note: This week's talk will be from 3:15 to 3:45 instead of the usual time.''
 
Title: Euler Spoilers
 
Abstract: Leonhard Euler is often cited as one of the greatest mathematicians of the 18. Century. His solution to the Königsburg Bridge problem is an important result of early topology. Euler also did work in combinatorics and in number theory. Often his methods tended to be computational in nature (he was a computer in the traditional sense) and from these he proposed many conjectures, a few of which turned out to be wrong. Two failed conjectures of Euler will be presented.
 
=== December 9, Brandon Alberts ===
 
Title: The field with one element
 
=== December 16, Micky Soule Steinberg ===
 
Title: Intersective polynomials
 
==Spring 2015==
 
===January 28, Moisés Herradón===
 
Title: Winning games and taking names
 
Abstract:  So let’s say we’re already amazing at playing one game (any game!) at a time and we now we need to play several games at once, to keep it challenging. We will see that doing this results in us being able to define an addition on the collection of all games, and that it actually turns this collection into a Group. I will talk about some of the wonders that lie within the group. Maybe lions? Maybe a field containing both the real numbers and the ordinals? For sure it has to be one of these two!
 
===February 11, Becky Eastham===
 
Title: A generalization of van der Waerden numbers: (a, b) triples and (a_1, a_2, ..., a_n) (n + 1)-tuples
 
Abstract: Van der Waerden defined w(k; r) to be the least positive integer such that for every r-coloring of the integers from 1 to w(k; r), there is a monochromatic arithmetic progression of length k.  He proved that w(k; r) exists for all positive k, r.  I will discuss the case where r = 2.  These numbers are notoriously hard to calculate: the first 6 of these are 1, 3, 9, 35, 178, and 1132, but no others are known.  I will discuss properties of a generalization of these numbers, (a_1, a_2, ..., a_n) (n + 1)-tuples, which are sets of the form {d, a_1x + d, a_2x + 2d, ..., a_nx + nd}, for d, x positive natural numbers.
 
===February 18, Solly Parenti===
 
Title: Chebyshev's Bias
 
Abstract: Euclid told us that there are infinitely many primes.  Dirichlet answered the question of how primes are distributed among residue classes.  This talk addresses the question of "Ya, but really, how are the primes distributed among residue classes?" Chebyshev noted in 1853 that there seems to be more primes congruent to 3 mod 4 than their are primes congruent to 1 mod 4.  It turns out, he was right, wrong, and everything in between.  No analytic number theory is presumed for this talk, as none is known by the speaker.
 
===February 25, David Bruce===
 
Title: Mean, Median, and Mode - Well Actually Just Median
 
Abstract: Given a finite set of numbers there are many different ways to measure the center of the set. Three of the more common measures, familiar to any middle school students, are: mean, median, mode. This talk will focus on the concept of the median, and why in many ways it's sweet. In particular, we will explore how we can extend the notion of a median to higher dimensions, and apply it to create more robust statistics. It will be awesome, and there will be donuts.
 
===March 4, Jing Hao===
 
Title: Error Correction Codes
 
Abstract: In the modern world, many communication channels are subject to noise, and thus errors happen. To help the codes auto-correct themselves, more bits are added to the codes to make them more different from each other and therefore easier to tell apart. The major object we study is linear codes. They have nice algebraic structure embedded, and we can apply well-known algebraic results to construct 'nice' codes. This talk will touch on the basics of coding theory, and introduce some famous codes in the coding world, including several prize problems yet to be solved!
 
===March 10 (Tuesday), Nathan Clement===
 
''Note: This week's seminar will be on Tuesday at 3:30 instead of the usual time.''
 
Title: Two Solutions, not too Technical, to a Problem to which the Answer is Two
 
Abstract: A classical problem in Algebraic Geometry is this: Given four pairwise skew lines, how many other lines intersect all of them. I will present some (two) solutions to this problem. One is more classical and ad hoc and the other introduces the Grassmannian variety/manifold and a little intersection theory.
 
===March 25, Eric Ramos===
 
Title: Braids, Knots and Representations
 
Abstract: In the 1920's Artin defined the braid group, B_n, in an attempt to understand knots in a more algebraic setting. A braid is a certain arrangement of strings in three-dimensional space. It is a celebrated theorem of Alexander that every knot is obtainable from a braid by identifying the endpoints of each string. Because of this correspondence, the Jones and Alexander polynomials, two of the most important knot invariants, can be described completely using the braid group. In fact, Jones was able to show that knot invariants can often be realized as characters of special representations of the braid group.
 
The purpose of this talk is to give a very light introduction to braid and knot theory. The majority of the talk will be comprised of drawing pictures, and nothing will be treated rigorously.
 
===April 8, James Waddington===
 
Title: Goodstein's Theorem
 
Abstract: One of the most important results in the development of mathematics are
Gödel's Incompleteness theorems. The first incompleteness theorem shows that no
list of axioms one could provide could extend number theory to a complete and
consistent theory. The second showed that one such statement was no
axiomatization of number theory could be used to prove its own consistency.
Needless to say this was not viewed as a very natural independent statement
from arithmetic.  
 
Examples of non-metamathematical results that were independent of PA, but true
of second order number theory, were not discovered until much later. Within a
short time of each three such statements that were more "natural" were
discovered. The Paris–Harrington Theorem, which was about a statement in Ramsey
theory, the Kirby–Paris theorem, which showed the independence of Goodstein's
theorem from Peano Arithmetic and the Kruskal's tree theorem, a statement about
finite trees.  
 
In this talk I shall discuss Goodstein's theorem which discusses the end
behavior of a certain "Zero player" game about k-nary expansions of numbers.
I will also give some elements of the proof of the Kirby–Paris theorem.
 
===April 22, William Cocke===
 
Title: Finite Groups aren't too Square
 
Abstract: We investigate how many non-p-th powers a group can have for a given prime p.
We will show using some elementary group theory, that if np(G) is the number of non-p-th powers
in a group G, then G has order bounded by np(G)(np(G)+1). Time permitting we will show this bound
is strict and that mentioned results involving more than finite groups.
 
==Fall 2014==
 
===September 25, Vladimir Sotirov===
 
Title: [[Media:Compact-openTalk.pdf|The compact open topology: what is it really?]]
 
Abstract:  The compact-open topology on the space C(X,Y) of continuous functions from X to Y is mysteriously generated by declaring that for each compact subset K of X and each open subset V of Y, the continous functions f: X->Y conducting K inside V constitute an open set. In this talk, I will explain the universal property that uniquely determines the compact-open topology, and sketch a pretty constellation of little-known but elementary facts from domain theory that dispell the mystery of the compact-open topology's definition.
 
===October 8, David Bruce===
 
Title: Hex on the Beach
 
Abstract: The game of Hex is a two player game played on a hexagonal grid attributed in part to John Nash. (This is the game he is playing in /A Beautiful Mind./) Despite being relatively easy to pick up, and pretty hard to master, this game has surprising connections to some interesting mathematics. This talk will introduce the game of Hex, and then explore some of these connections. *As it is a lot more fun once you've actually played Hex feel free to join me at 3:00pm on the 9th floor to actually play a few games of Hex!*
 
===October 22, Eva Elduque===
 
Title: The fold and one cut problem
 
Abstract: What shapes can we get by folding flat a piece of paper and making (only) one complete straight cut? The answer is surprising: We can cut out any shape drawn with straight line segments. In the talk, we will discuss the two methods of approaching this problem, focusing on the straight skeleton method, the most intuitive of the two.
 
===November 5, Megan Maguire===
 
Title: Train tracks on surfaces
 
Abstract: What is a train track, mathematically speaking? Are they interesting? Why are they interesting? Come find out!
 
===November 19, Adrian Tovar-Lopez===
 
Title:  Hodgkin and Huxley equations of a single neuron
 
===December 3, Zachary Charles===
 
Title:  Addition chains: To exponentiation and beyond
 
Abstract: An addition chain is a sequence of numbers starting at one, such that every number is the sum of two previous numbers. What is the shortest chain ending at a number n? While this is already difficult, we will talk about how addition chains answer life's difficult questions, including: How do we compute 2^4? What can the Ancient Egyptians teach us about elliptic curve cryptography? What about subtraction?

Latest revision as of 18:18, 20 November 2024

The AMS Student Chapter Seminar (aka Donut Seminar) is an informal, graduate student seminar on a wide range of mathematical topics. The goal of the seminar is to promote community building and give graduate students an opportunity to communicate fun, accessible math to their peers in a stress-free (but not sugar-free) environment. Pastries (usually donuts) will be provided.

  • When: Thursdays 4:00-4:30pm
  • Where: Van Vleck, 9th floor lounge (unless otherwise announced)
  • Organizers: Ivan Aidun, Kaiyi Huang, Ethan Schondorf

Everyone is welcome to give a talk. To sign up, please contact one of the organizers with a title and abstract. Talks are 25 minutes long and should avoid assuming significant mathematical background beyond first-year graduate courses.

The schedule of talks from past semesters can be found here.

Fall 2024

Date Speaker Title Abstract
September 12 Ari Davidovsky 95% of people can't solve this! Image.png

We will attempt to answer this question and along the way explore how algebra and geometry work together to solve problems in number theory.

September 19 CANCELLED NONE NONE
September 26 Mateo Morales Officially petitioning the department to acquire a ping pong table. Ever want to prove something is a free group of rank 2? Me too. One way to do this is to use a ping pong argument of how a group generated by two elements acts on a set.

I will illustrate the ping pong argument using an example of matrices, explain how it works, and explain why, kinda.

Very approachable if you know what a group is but does require tons of ping pong experience.

October 3 Karthik Ravishankar Incompleteness for the working mathematician In this talk we'll take a look at Gödels famous incompleteness theorems and look at some of its immediate as well as interesting consequences. No background in logic is necessary!
October 10 Elizabeth Hankins Mathematical Origami and Flat-Foldability If you've ever unfolded a piece of origami, you might have noticed complicated symmetries in the pattern of creases left behind. What patterns of lines can and cannot be folded into origami? And why is it sometimes hard to determine?
October 17 CANCELLED NONE NONE
October 24 CANCELLED NONE NONE
October 31 Jacob Wood What is the length of a potato pumpkin? How many is a jack-o-lantern? What is the length of a pumpkin? These questions sound like nonsense, but they have perfectly reasonable interpretations with perfectly reasonable answers. On our journey through the haunted house with two rooms, we will encounter some scary characters like differential topology and measure theory. Do not fear; little to no experience in either subject is required.
November 7 CANCELLED: DISTINGUISHED LECTURE NONE NONE
November 14 Sapir Ben-Shahar Hexaflexagons Come along for some hexaflexafun and discover the mysterious properties of hexaflexagons, the bestagons! Learn how to make and navigate through the folds of your very own paper hexaflexagon. No prior knowledge of hexagons (or hexaflexagons) is assumed.
November 21 Andrew Krenz All concepts are database queries A celebrated result of applied category theory states that the category of small categories is equivalent to the category of database schemas. Therefore, every theorem about small categories can be interpreted as a theorem about databases.  Maybe you've heard someone repeat Mac Lane's famous slogan "all concepts are Kan extensions."  In this talk, I'll give a high-level overview of/introduction to categorical database theory (developed by David Spivak) wherein Kan extensions play the role of regular every day database queries.  No familiarity with categories or databases will be assumed.
November 28 THANKSGIVING NONE NONE
December 5 Caroline Nunn TBA T
Retrieved from "https://wiki.math.wisc.edu/index.php?title=AMS_Student_Chapter_Seminar&oldid=27633"