Previous Conferences & Workshops

Feb
15
2021

Members’ Seminar

No seminar: Presidents' Day
2:00pm|Simonyi Hall 101 and Remote Access
Feb
15
2021

Computer Science/Discrete Mathematics Seminar I

Monotone Arithmetic Circuit Lower Bounds Via Communication Complexity
Arkadev Chattopadhyay
11:15am|Remote Access - see Zoom link below

Valiant (1980) showed that general arithmetic circuits with negation can be exponentially more powerful than monotone ones. We give the first qualitative improvement to this classical result: we construct a family of polynomials P-n in n variables...

Feb
11
2021

Joint IAS/Princeton University Number Theory Seminar

Cohomology of Arithmetic Groups and Endoscopy
Mathilde Gerbelli-Gauthier
4:30pm|Remote Access

How fast do Betti numbers grow in a congruence tower of compact arithmetic manifolds? The dimension of the middle degree of cohomology is proportional to the volume of the manifold, but away from the middle the growth is known to be sub-linear in...

Feb
11
2021

Quantum Groups Seminar

Center of quantum group
Arun Kannan
4:00pm|Remote Access

Continuation of the talk from Feb 4.

Feb
10
2021

Mathematical Conversations

Quantum Integer Valued Polynomials
Nate Harman
5:30pm|Remote Access

In algebraic combinatorics there well known objects called q-integers, q-binomial coefficients, and q-factorials which for lack of a better word "q-ify" the usual integers, binomial coefficients, and factorials. I will explain these notions (and say...

Feb
10
2021

Geometric and Modular Representation Theory Seminar

Equivariantization and de-equivariantization
Shotaro Makisumi
3:00pm|Simonyi Hall 101 and Remote Access

This is the second in a series of talks on "two realizations." We discuss equivariantization and de-equivariantization for a group $G$, which relate categories with $G$-actions and categories with RepG-actions, and how this relates to the notion of...

Feb
10
2021

Stability and Testability

Non-amenable groups admitting no sofic approximation by expander graphs
Gabor Kun
11:00am|Remote Access
We show that the direct product of an infinite, finitely generated Kazhdan Property (T) group and a finitely presented, not residually finite amenable group admits no sofic approximation by expander graphs. Joint work with Andreas Thom.