Previous Conferences & Workshops

Oct
28
2025

Joint IAS/PU Groups and Dynamics Seminar

Classifying Hyperbolic Ergodic Stationary Measures on K3 Surfaces with Large Automorphism Groups
4:30pm|314 Fine Hall

Let $X$ be a K3 surface. Consider a finitely supported probability measure $\mu$ on $\operatorname{Aut}(X)$ such that $\Gamma_{\mu} = \langle \operatorname{Supp}(\mu)\rangle Aut(X)$ is non-elementary. We do not assume that $\Gamma_{\mu}$ contains...

Oct
28
2025

Joint IAS/PU Symplectic Geometry Seminar

Divisor Complements, Floer Homotopy, and Spectral Gromov-Witten Theory
Kenny Blakey
1:00pm|Fine Hall 401

Work of Diogo, Diogo-Lisi, and Ganatra-Pomerleano have explored the idea of computing symplectic cohomology of a divisor complement. In particular, we may compute the associated graded of the standard action filtration on symplectic cohomology in...

Oct
28
2025

Computer Science/Discrete Mathematics Seminar II

Aldous-type Spectral Gaps in Unitary Groups, Part II
10:30am|Simonyi 101 and Remote Access

Around 1992, Aldous made the following bold conjecture. Let A be any set of transpositions in the symmetric group Sym(N). Then the spectral gap of the Cayley graph Cay(Sym(N),A) is identical to that of a relatively tiny N-vertex graph defined by A...

Oct
27
2025

Joint IAS/PU Arithmetic Geometry

Geometric Shafarevich Conjecture for Exceptional Shimura Varieties
3:15pm|Princeton University, Fine Hall 224

The Shafarevich conjecture is concerned with finiteness results for families of g-dimensional principally polarized abelian varieties over a base B. Famously, Faltings settled the arithmetic case of B=O_{K,S}. In the case where B is a curve over a...

Oct
27
2025

Members' Colloquium

O-Minimality and Rational Numbers
1:30pm|Simonyi 101 and Remote Access

I'll give a brief introduction to o-minimality and how it can be used to prove asymptotic estimates for the number of rational points in definable sets. I'll then show how problems from various areas of mathematics can be reformulated as questions...

Oct
27
2025

Computer Science/Discrete Mathematics Seminar I

Explicit Lossless Vertex Expanders
Rachel Zhang
11:00am|Simonyi Hall 101 and Remote Access

In this talk, I will describe our construction of the first explicit lossless vertex expanders. These are graphs where every small subset of vertices has about as many neighbors as their sparsity allows. Previously, the strongest known explicit...

Oct
24
2025

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

Arnol'd's Chord Conjecture for Conormal Legendrian Lifts
Filip Broćić
9:15am|Remote Access

The chord conjecture, due initially to Arnol'd in the case of the standard contact three-sphere, asserts the existence of a Reeb chord with boundary on every closed Legendrian submanifold of a closed contact manifold for every contact form. This...

Oct
23
2025

Joint IAS/PU Number Theory

Shioda’s Conjecture on Unirationality
Ben Church
3:30pm|Simonyi 101 and Remote Access

In characteristic zero, Castelnuovo proved that every unirational surface is rational. In positive characteristic, this fails dramatically: there exist many non-rational, often even general-type, surfaces that are nevertheless unirational. In 1977...

Oct
23
2025

Special Year Research Seminar

Preparation and Point Counting in Sharply O-minimal Structures
Oded Carmon
1:00pm|Simonyi 101

I will describe recent work in progress on logarithmic--exponential preparation theorems in analytically generated sharply o-minimal structures. Our results imply the sharp o-minimality of $\mathbb{R}_{\exp}$ as well as a uniform version of Wilkie’s...

Oct
23
2025

What is...?

What is Property $\tau$
Alex Lubotzky
11:30am|Simonyi 101 and Remote Access

Property (T) was defined by Kazhdan in the 1960s, who used it to prove two conjectures of Selberg on lattices in high-rank Lie groups. Shortly after that, Margulis used it to construct expander graphs.

Property $\tau$ is a baby version of property (T...