Graduate Algebraic Geometry Seminar Spring 2022: Difference between revisions

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| bgcolor="#BCD2EE" width="300" align="center"|'''Title (click to see abstract)'''
| bgcolor="#BCD2EE" width="300" align="center"|'''Title (click to see abstract)'''
|-
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| bgcolor="#E0E0E0"| February 2
| bgcolor="#E0E0E0"| February 3
| bgcolor="#C6D46E"|  
| bgcolor="#C6D46E"|
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#January 29| ]]
| bgcolor="#BCE2FE"|[[#February 3| ]]
|-
|-
| bgcolor="#E0E0E0"| February 5
| bgcolor="#E0E0E0"| February 10
| bgcolor="#C6D46E"| Asvin Gothandaraman
| bgcolor="#C6D46E"| Asvin Gothandaraman
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#February 5| An Introduction to Unirationality]]
| bgcolor="#BCE2FE"|[[#February 10| ]]
|-
|-
| bgcolor="#E0E0E0"| February 12
| bgcolor="#E0E0E0"| February 17
| bgcolor="#C6D46E"| Qiao He
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#February 12| Title]]
| bgcolor="#BCE2FE"|[[#February 17| ]]
|-
|-
| bgcolor="#E0E0E0"| February 19
| bgcolor="#E0E0E0"| February 24
| bgcolor="#C6D46E"| Dima Arinkin
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#February 19| Blowing down, blowing up: surface geometry]]
| bgcolor="#BCE2FE"|[[#February 24| ]]
|-
|-
| bgcolor="#E0E0E0"| February 26
| bgcolor="#E0E0E0"| March 3
| bgcolor="#C6D46E"| Connor Simpson
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#February 26| Intro to toric varieties]]
| bgcolor="#BCE2FE"|[[#March 3| ]]
|-
|-
| bgcolor="#E0E0E0"| March 4
| bgcolor="#E0E0E0"| March 10
| bgcolor="#C6D46E"| Peter
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#March 4| An introduction to Grothendieck-Riemann-Roch Theorem]]
| bgcolor="#BCE2FE"|[[#March 10| ]]
|-
|-
| bgcolor="#E0E0E0"| March 11
| bgcolor="#E0E0E0"| March 24
| bgcolor="#C6D46E"| Caitlyn Booms
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#March 11| Intro to Stanley-Reisner Theory]]
| bgcolor="#BCE2FE"|[[#March 24| ]]
|-
|-
| bgcolor="#E0E0E0"| March 25
| bgcolor="#E0E0E0"| March 31
| bgcolor="#C6D46E"| Steven He
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#March 25| Braid group action on derived categories]]
| bgcolor="#BCE2FE"|[[#March 31| ]]
|-
|-
| bgcolor="#E0E0E0"| April 1
| bgcolor="#E0E0E0"| April 7
| bgcolor="#C6D46E"| Vlad Sotirov
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#April 1| Title]]
| bgcolor="#BCE2FE"|[[#April 7| ]]
|-
|-
| bgcolor="#E0E0E0"| April 8
| bgcolor="#E0E0E0"| April 14
| bgcolor="#C6D46E"| Maya Banks
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#April 8| Title]]
| bgcolor="#BCE2FE"|[[#April 14| ]]
|-
|-
| bgcolor="#E0E0E0"| April 15
| bgcolor="#E0E0E0"| April 21
| bgcolor="#C6D46E"| Alex Hof
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#April 15| Embrace the Singularity: An Introduction to Stratified Morse Theory]]
| bgcolor="#BCE2FE"|[[#April 21| ]]
|-
|-
| bgcolor="#E0E0E0"| April 22
| bgcolor="#E0E0E0"| April 28
| bgcolor="#C6D46E"| Ruofan
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#April 22| Birational geometry: existence of rational curves]]
| bgcolor="#BCE2FE"|[[#April 28| ]]
|-
|-
| bgcolor="#E0E0E0"| April 29
| bgcolor="#E0E0E0"| May 5
| bgcolor="#C6D46E"| John Cobb
| bgcolor="#C6D46E"|  
| bgcolor="#BCE2FE"|[[Graduate Algebraic Geometry Seminar#April 29| Title]]
| bgcolor="#BCE2FE"|[[#May 5| ]]
|}
|}
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=== January 29 ===
=== February 3 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Colin Crowley'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Lefschetz hyperplane section theorem via Morse theory
| bgcolor="#BCD2EE"  align="center" | Title:  
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| bgcolor="#BCD2EE"  | Abstract: Morse theory allows you to learn about the topology of a manifold by studying the critical points of a nice function on the manifold. This perspective produces a nice proof of the theorem in the title, which concerns the homology of smooth projective varieties over C. I'll explain what the theorem says, say something about what Morse theory is and why it's related, and then finish with a neat example. I'm aiming to make this understandable to someone who's taken algebraic geometry 1 and topology 1.
| bgcolor="#BCD2EE"  | Abstract:
|}                                                                         
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=== February 5 ===
=== February 10 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
|-
| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Asvin Gothandaraman '''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: An introduction to unirationality
| bgcolor="#BCD2EE"  align="center" | Title:  
|-
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| bgcolor="#BCD2EE"  | Abstract: I will introduce the notion of unirationality and show that cubic hypersurfaces are unirational (following Kollar). If time permits, I will also show that unirational varieties are simply connected.
| bgcolor="#BCD2EE"  | Abstract:  
|}                                                                         
|}                                                                         
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=== February 12 ===
=== February 17 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Qiao He'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
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| bgcolor="#BCD2EE"  align="center" | Title:  
| bgcolor="#BCD2EE"  align="center" | Title:  
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=== February 19 ===
=== February 24 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
|-
| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Dima Arinkin'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
|-
| bgcolor="#BCD2EE"  align="center" | Title: Blowing down, blowing up: surface geometry
| bgcolor="#BCD2EE"  align="center" | Title:  
|-
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| bgcolor="#BCD2EE"  | Abstract:A big question in algebraic geometry is how much one can change a variety without affecting it `generically'. More precisely, if two varieties are birational, how far can they be from being isomorphic?
| bgcolor="#BCD2EE"  | Abstract:
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The question is trivial for (smooth projective) curves: they are birational if and only if they are isomorphic. In higher dimension, the
=== March 3 ===
situation is much more interesting. The most fundamental operation are the `blowup', which is a kind of alteration of a variety within its birational isomorphism class, and its opposite, the blowdown.
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
In my talk, I will introduce blowups and discuss their properties. Then (time permitting) I would like to look deeper at the case
|-
of surfaces, where the combination of blowups and intersection theory provides a complete and beautiful picture. (If we do get to this point, I won't assume any knowledge of intersection theory: to an extent, this talk is my excuse to introduce it.)
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
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| bgcolor="#BCD2EE"  align="center" | Title:
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| bgcolor="#BCD2EE"  | Abstract:
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=== February 26 ===
=== March 10 ===
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<center>
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
|-
| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Connor Simpson'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Intro to Toric Varieties
| bgcolor="#BCD2EE"  align="center" | Title:  
|-
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| bgcolor="#BCD2EE"  | Abstract: A brief introduction to toric varieties: how to build them, formulas for computing topological data, toric blow-ups, and more.
| bgcolor="#BCD2EE"  | Abstract:  
|}                                                                         
|}                                                                         
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=== March 4 ===
=== March 17 ===
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<center>
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
|-
| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Peter Wei'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: An introduction to Grothendieck-Riemann-Roch Theorem
| bgcolor="#BCD2EE"  align="center" | Title:  
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| bgcolor="#BCD2EE"  | Abstract: The classical Riemann-Roch theorem tells you about how topological (genus) and analytical (through line bundle) properties on compact Riemann surface (i.e. smooth projective curve) relate to each other. Moreover, this theorem can be generalized to any vector bundles (or coherent sheaves) over any smooth projective varieties. Eventually, Grothendieck “relativized” this theorem as a property of a morphism between two projective varieties. In this talk I will introduce basic notions to formulate this theorem. If time permitting, enough examples will be given appropriately.
| bgcolor="#BCD2EE"  | Abstract:  
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|}                                                                         
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=== March 11 ===
=== March 24 ===
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<center>
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
|-
| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Caitlyn Booms'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Intro to Stanley-Reisner Theory
| bgcolor="#BCD2EE"  align="center" | Title:  
|-
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| bgcolor="#BCD2EE"  | Abstract: Stanley-Reisner theory gives a dictionary between combinatorial objects (simplicial complexes) and algebraic objects (Stanley-Reisner rings). In this talk, I will introduce the main objects of study in this theory, describe this dictionary with several examples, and discuss how Stanley-Reisner theory can help us investigate algebra-geometric questions.
| bgcolor="#BCD2EE"  | Abstract:  
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=== March 25 ===
=== March 31 ===
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<center>
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Steven He'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Braid group action on derived category
| bgcolor="#BCD2EE"  align="center" | Title:  
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| bgcolor="#BCD2EE"  | Abstract: In this talk, I will define spherical object and A_m-configuration in derived category of coherent sheaves, and say a few words about the motivation coming from the homological mirror symmetry.
| bgcolor="#BCD2EE"  | Abstract:  
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=== April 1 ===
=== April 7 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Vlad Sotirov'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
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| bgcolor="#BCD2EE"  align="center" | Title:  
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=== April 8 ===
=== April 14 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Maya Banks'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
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=== April 15 ===
=== April 21 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Alex Hof'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Embrace the Singularity: An Introduction to Stratified Morse Theory
| bgcolor="#BCD2EE"  align="center" | Title:  
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| bgcolor="#BCD2EE"  | Abstract:  
| bgcolor="#BCD2EE"  | Abstract: Early on in the semester, Colin told us a bit about Morse
Theory, and how it lets us get a handle on the (classical) topology of
smooth complex varieties. As we all know, however, not everything in
life goes smoothly, and so too in algebraic geometry. Singular
varieties, when given the classical topology, are not manifolds, but
they can be described in terms of manifolds by means of something called
a Whitney stratification. This allows us to develop a version of Morse
Theory that applies to singular spaces (and also, with a bit of work, to
smooth spaces that fail to be nice in other ways, like non-compact
manifolds!), called Stratified Morse Theory. After going through the
appropriate definitions and briefly reviewing the results of classical
Morse Theory, we'll discuss the so-called Main Theorem of Stratified
Morse Theory and survey some of its consequences.
|}                                                                         
|}                                                                         
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=== April 22 ===
=== April 28 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''Ruofan'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
|-
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| bgcolor="#BCD2EE"  align="center" | Title: Birational geometry: existence of rational curves
| bgcolor="#BCD2EE"  align="center" | Title:  
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| bgcolor="#BCD2EE"  | Abstract: Rational curves on a variety control its birational geometry. It thus is important to determine whether they exist. People didn’t know how to do this systematically, before Mori discovered a deformation lemma which detect their existence, and bound their degree if they exist. I will briefly introduce Mori’s insight.
| bgcolor="#BCD2EE"  | Abstract:  
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|}                                                                         
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=== April 29 ===
=== May 5 ===
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{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"
|-
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| bgcolor="#A6B658" align="center" style="font-size:125%" | '''John Cobb'''
| bgcolor="#A6B658" align="center" style="font-size:125%" | ''''''
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| bgcolor="#BCD2EE"  align="center" | Title:  
| bgcolor="#BCD2EE"  align="center" | Title:  

Revision as of 00:35, 15 January 2022

When: TBD

Where: TBD

Lizzie the OFFICIAL mascot of GAGS!!

Who: All undergraduate and graduate students interested in algebraic geometry, commutative algebra, and related fields are welcome to attend.

Why: The purpose of this seminar is to learn algebraic geometry and commutative algebra by giving and listening to talks in a informal setting. Sometimes people present an interesting paper they find. Other times people give a prep talk for the Algebraic Geometry Seminar. Other times people give a series of talks on a topic they have been studying in-depth. Regardless the goal of GAGS is to provide a supportive and inclusive place for all to learn more about algebraic geometry and commutative algebra.

How: If you want to get emails regarding time, place, and talk topics (which are often assigned quite last minute) add yourself to the gags mailing list: gags@g-groups.wisc.edu by sending an email to gags+subscribe@g-groups.wisc.edu. If you prefer (and are logged in under your wisc google account) the list registration page is here.

Organizers: John Cobb, Colin Crowley.

Give a talk!

We need volunteers to give talks this semester. If you're interested, please fill out this form. Beginning graduate students are particularly encouraged to give a talk, since it's a great way to get your feet wet with the material. If you would like some talk ideas, see the list on the main page.

Spring 2022 Topic Wish List

This was assembled using input from an interest form at the beginning of the semester. Choose one and you will have the rare guarantee of having one interested audience member. Feel free to add your own.

  • Computing things about Toric varieties
  • Reductive groups and flag varieties
  • Geothendieck '66, "On the de Rham Cohomology of Algebraic Varieties"
  • Going from line bundles and divisors to vector bundles and chern classes
  • A History of the Weil Conjectures
  • Mumford & Bayer, "What can be computed in Algebraic Geometry?"
  • A pre talk for any other upcoming talk

Being an audience member

The goal of GAGS is to create a safe and comfortable space inclusive of all who wish to expand their knowledge of algebraic geometry and commutative algebra. In order to promote such an environment in addition to the standard expectations of respect/kindness all participants are asked to following the following guidelines:

  • Do Not Speak For/Over the Speaker
  • Ask Questions Appropriately

Talks

Date Speaker Title (click to see abstract)
February 3
February 10 Asvin Gothandaraman
February 17
February 24
March 3
March 10
March 24
March 31
April 7
April 14
April 21
April 28
May 5

February 3

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February 10

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February 17

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February 24

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March 3

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March 10

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March 17

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March 24

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March 31

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April 7

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April 14

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April 21

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April 28

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May 5

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Past Semesters

Fall 2021

Spring 2021

Fall 2020

Spring 2020

Fall 2019

Spring 2019

Fall 2018

Spring 2018

Fall 2017

Spring 2017

Fall 2016

Spring 2016

Fall 2015