Seminars Sorted by Series

Working Seminar on Nonabelian Hodge Theory

Working Seminar on Representation Theory

Oct
19
2016

Working Seminar on Representation Theory

Categorification of the positive half of $\mathbb{U}_q(\mathfrak{sl}_2)$
11:00am|S-101

We will talk about the categorification of the positive half of the quantum group $\mathbb{U}_q(\mathfrak{sl}_2)$ using the module categories over NilHecke algebras. We hope to explain the idea of categorification using this example.

Nov
09
2016

Working Seminar on Representation Theory

$\mathbb C$-representation theory of $p$-adic groups through the glass of types
11:00am|S-101

It is well known that representations of open compact subgroups (called types) play a fundamental role in studying representations of $p$-adic groups. We give an overview of the theory (after Bernstein, Moy-Prasad, Bushnell-Kutzko) in connection...

Dec
07
2016

Working Seminar on Representation Theory

Mirror symmetry on the Bruhat-Tits building and representations of $p$-adic groups
11:00am|S-101

It is an old question in representation theory whether any finitely-generated smooth representation of a $p$-adic group has a resolution by representations induced from (finite-dimensional representations of) compact subgroups. We construct such a...

Jan
27
2017

Working Seminar on Representation Theory

A Gelfand-Graev Formula and Stable Transfer Factors for $mathrm{SL}_n$
Daniel Johnstone
2:00pm

A result of Gelfand and Graev shows that the supercuspidal representations of $\mathrm{SL}_2$ are neatly parameterized by characters of elliptic tori, and that the stable character data for all such representations may be collected into a single...

Feb
10
2017

Working Seminar on Representation Theory

Canonical bases arising from quantum symmetric pairs
2:00pm

A quantum symmetric pair consists of a quantum group and its coideal subalgebra. The coideal subalgebra is a quantum analog of the fixed point subalgebra of the enveloping algebra with respect to certain involution. In this talk, we shall describe...

Feb
24
2017

Working Seminar on Representation Theory

Cocenters and representations of affine Hecke algebras
2:00pm

It is known that the number of conjugacy classes of a finite group equals the number of irreducible representations (over complex numbers). The conjugacy classes of a finite group give a natural basis of the cocenter of its group algebra. Thus the...

Workshop on Additive Combinatorics and Algebraic Connections

Oct
24
2022

Workshop on Additive Combinatorics and Algebraic Connections

Random Character Varieties
10:00am|Simonyi 101 and Remote Access

Abstract: Irreducibility of random polynomials of large degree has been studied recently in works by several authors (in particular by Bary-Soroker, Kozma, Koukoulopoulos and by Varju and myself). We study analogous problems in the setting of word...

Oct
24
2022

Workshop on Additive Combinatorics and Algebraic Connections

The Polynomial Method and High-degree Varieties
Miguel Walsh
11:15am|Simonyi 101 and Remote Access

Abstract: We will discuss some results on high-degree varieties designed to expand the reach of the polynomial method and explain their applications in incidence geometry.

Oct
24
2022

Workshop on Additive Combinatorics and Algebraic Connections

The Failure of the Periodic Tiling Conjecture
2:00pm|Simonyi 101 and Remote Access

Abstract: Translational tiling is a covering of a space using translated copies of a building block, called a "tile", without any positive measure overlaps. What are the possible ways that a space can be tiled?
The most well known conjecture in this...

Oct
25
2022

Workshop on Additive Combinatorics and Algebraic Connections

Polynomial Maps With Noisy Input-Distributions
Jop Briet
10:00am|Simonyi 101 and Remote Access

Abstract: A problem from theoretical computer science posed by Buhrman asks to show that a certain class of circuits (NC0[+]) is bad at decoding error correcting codes under random noise. (This would be in contrast with an analogous class of quantum...

Oct
25
2022

Workshop on Additive Combinatorics and Algebraic Connections

Ranks of Tensors
11:15am|Simonyi 101 and Remote Access

Abstract: Several equivalent definitions of rank for matrices yield non-equivalent definitions of rank when generalized to higher order tensors. Understanding the interplay between these different definitions is related to important questions in...

Oct
25
2022

Workshop on Additive Combinatorics and Algebraic Connections

The Monomial Structure of Boolean Functions
2:00pm|Simonyi 101 and Remote Access

Abstract: Let $f:{0,1}^n$ to ${0,1}$ be a boolean function. It can be uniquely represented as a multilinear polynomial. What is the structure of its monomials? This question turns out to be connected to some well-studied problems, such as the log...

Oct
25
2022

Workshop on Additive Combinatorics and Algebraic Connections

The Alon-Jaeger-Tarsi Conjecture via Group Ring Identities
Peter Pach
4:00pm|Simonyi 101 and Remote Access

Abstract: The Alon-Jaeger-Tarsi conjecture states that for any finite field $F$ of size at least 4  and any nonsingular  matrix $M$ over $F$ there exists a vector $x$ such that neither $x$ nor $Mx$ has a 0 component. In this talk we discuss the...

Oct
26
2022

Workshop on Additive Combinatorics and Algebraic Connections

Tensorial Forms in Infinite Dimensions
Andrew Snowden
10:00am|Simonyi 101 and Remote Access

Abstract: Let V be a complex vector space and consider symmetric d-linear forms on V, i.e., linear maps $Sym^d(V) \rightarrow > C$. When V is finite dimensional and $d>2$, the structure of such forms is very complicated. Somewhat surprisingly, when...

Oct
26
2022

Workshop on Additive Combinatorics and Algebraic Connections

G-stable Rank and the Cap Set Problem
Harm Derksen
11:15am|Simonyi 101 and Remote Access

Abstract: Ellenberg and Gijswijt drastically improved the best known upper asymptotic bound for the cardinality of a cap set in 2016. Tao introduced the notion of slice rank for tensors and showed that the Ellenberg-Gijswijt proof can be nicely...

Oct
26
2022

Workshop on Additive Combinatorics and Algebraic Connections

On Tensor Properties Preserved Under Linear Maps
2:00pm|Simonyi 101 and Remote Access

Abstract: A theorem by Kazhdan and Ziegler says that any property of homogeneous polynomials---of a fixed degree but in an arbitrary number of variables---that is preserved under linear maps is either satisfied by all polynomials or else implies a...

Oct
27
2022

Workshop on Additive Combinatorics and Algebraic Connections

Bounds for Subsets of $\mathbb{F}_p^n \times \mathbb{F}_p^n$ without L-shaped Configurations
10:00am|Simonyi 101 and Remote Access

Abstract: I will discuss the difficult problem of proving reasonable bounds in the multidimensional generalization of Szemer\’edi’s theorem and describe a proof of such bounds for sets lacking nontrivial configurations of the form $(x,y), (x,y+z),...

Oct
27
2022

Workshop on Additive Combinatorics and Algebraic Connections

Quantitative Inverse Theorem for Gowers Uniformity Norms $\mathsf{U}^5$ and $\mathsf{U}^6$ in $\mathbb{F}_2^n$
Luka Milicevic
11:15am|Simonyi 101 and Remote Access

Abstract: In this talk, I will discuss a proof of a quantitative version of the inverse theorem for Gowers uniformity norms $\mathsf{U}^5$ and $\mathsf{U}^6$ in $\mathbb{F}_2^n$. The proof starts from an earlier partial result of Gowers and myself...

Oct
27
2022

Workshop on Additive Combinatorics and Algebraic Connections

Higher Order Stability and Quadratic Arithmetic Regularity Lemmas
Caroline Terry
2:00pm|Simonyi 101 and Remote Access

Abstract: We present recent work, joint with J. Wolf, in which we define a natural ternary analogue of the order property, called the functional order properly, and show that subsets of $F_p^n$ without the functional order property admit especially...

Oct
28
2022

Workshop on Additive Combinatorics and Algebraic Connections

Towards a Geometric Analogue of Sarnak's Conjecture
Will Sawin
10:00am|Simonyi 101 and Remote Access

Abstract: Work of Mark Shusterman and myself has proven an analogue of Chowla's conjecture for polynomial rings over finite fields, which controls k-points correlations of the Möbius function for k bounded by a certain function of the finite field...

Oct
28
2022

Workshop on Additive Combinatorics and Algebraic Connections

Approximate Lattices in Algebraic Groups
11:15am|Simonyi 101 and Remote Access

Abstract: Approximate lattices in locally compact groups are approximate subgroups that are discrete and have finite co-volume. They provide natural examples of objects at the intersection of algebraic groups, ergodic theory and additive...

Oct
28
2022

Workshop on Additive Combinatorics and Algebraic Connections

Product Free Sets in Groups
2:00pm|Simonyi 101 and Remote Access

Abstract: A subset of a group is said to be product free if it does not contain the product of two elements in it. We consider how large can a product free subset of the alternating group $A_n$ be? 

In the talk we will completely solve the problem...

Workshop on Analytic Number Theory

Workshop on Chow groups, motives and derived categories