Previous Conferences & Workshops

Feb
19
2021

Joint IAS/Princeton/Montreal/Paris/Tel-Aviv Symplectic Geometry Zoominar

Intrinsic mirror symmetry and categorical crepant resolutions
Daniel Pomerleano
9:15am|Remote Access

Gross and Siebert have recently proposed an "intrinsic" programme for studying mirror symmetry. In this talk, we will discuss a symplectic interpretation of some of their ideas in the setting of affine log Calabi-Yau varieties. Namely, we describe...

Feb
18
2021

Joint IAS/Princeton University Number Theory Seminar

Exceptional jumps of Picard rank of K3 surfaces over number fields
4:30pm|Remote Access

Given a K3 surface $X$ over a number field $K$, we prove that the set of primes of $K$ where the geometric Picard rank jumps is infinite, assuming that $X$ has everywhere potentially good reduction. This result is formulated in the general framework...

Feb
17
2021

Mathematical Conversations

Why is $N_{\Gamma_0(12)}^{\mathrm{new}}(\lambda)$ of cocompact type?
5:30pm|Remote Access

I will speak, broadly, on, the arithmetic and geometry of quaternion algebras and aspects of the spectral theory of automorphic laplacians. I will describe spectral correspondences between spaces of Maass waveforms on the unit group of a quaternion...

Feb
17
2021

Geometric and Modular Representation Theory Seminar

Gaitsgory's central sheaves
3:00pm|Simonyi Hall 101 and Remote Access

A theorem of Bernstein identifies the center of the affine Hecke algebra of a reductive group $G$ with the Grothendieck ring of the tensor category of representations of the dual group $G^\vee$. Gaitsgory constructed a functor which categrorifies...

Feb
17
2021

Stability and Testability

Matrix stability of crystallographic groups
Soren Eilers
11:00am|Remote Access

Some years ago, I proved with Shulman and Sørensen that precisely 12 of the 17 wallpaper groups are matricially stable in the operator norm. We did so as part of a general investigation of when group $C^*$-algebras have the semiprojectivity and weak...

Feb
16
2021

SL2 Seminar

Tilting Character Computations II
3:00pm|Remote Access

In this talk, we will put together all ingredients we have seen in the last couple of talks to describe the algorithm to calculate tilting characters for reductive algebraic groups in the anti-spherical module. We will try to illustrate the most...

Feb
16
2021

Computer Science/Discrete Mathematics Seminar II

High dimensional expanders - Part 2
10:30am|Remote Access - see Zoom link below

Expander graphs are graphs which simultaneously are both sparse and highly connected. The theory of expander graphs received a lot of attention in the past half a century, from both computer science and mathematics. In recent years, a new theory of...