Seminars Sorted by Series

Joint IAS/PU Groups and Dynamics Seminar

Dec
16
2025

Joint IAS/PU Groups and Dynamics Seminar

Partially Hyperbolic Actions of Semisimple Lie Groups
Kurt Vinhage
4:30pm|Simonyi 101

Zimmer proposed the study of higher-rank semisimple group actions in the 1980's after showing certain rigidity results, especially about associated cocycles in the measurable category. In this talk, I will describe recent progress towards...

Joint IAS/PU Number Theory

Oct
09
2025

Joint IAS/PU Number Theory

On Uniform Boundedness of Torsion Points for Abelian Varieties Over Function Fields
Jit Wu Yap
3:30pm|Simonyi 101 and Remote Access

Let K be the function field of a smooth projective curve B over the complex numbers and let g be a positive integer. The uniform boundedness conjecture predicts that there exists a constant N, depending only on g and K, such that for any g...

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...

Nov
06
2025

Joint IAS/PU Number Theory

Motivic Action Conjecture for Doi-Naganuma Lifts
Yingkun Li
3:30pm|Simonyi 101 and Remote Access

A surprising property of the cohomology of locally symmetric spaces is that Hecke operators can act on multiple cohomological degrees with the same eigenvalues. In a series of papers, Venkatesh and his collaborators proposed an arithmetic reason for...

Nov
20
2025

Joint IAS/PU Number Theory

From Automorphic Periods to Arithmetic: The Case of Hilbert Modular Forms
3:30pm|Simonyi 101 and Remote Access

The theory of Euler systems, first developed by Thaine and Kolyvagin, has become a central tool for proving cases of the Birch–Swinnerton-Dyer and Bloch–Kato conjectures. Many of the known examples are inspired from automorphic period integrals that...

Dec
04
2025

Joint IAS/PU Number Theory

On Triple Product L-Functions
Miao Gu
3:30pm|Simonyi 101 and Remote Access

The Poisson summation conjecture of Braverman-Kazhdan, L. Lafforgue, Ngo, and Sakellaridis is an ambitious proposal to prove analytic properties of quite general Langlands L-functions using vast generalizations of the Poisson summation formula. In...

Dec
11
2025

Joint IAS/PU Number Theory

Simultaneous Non-Vanishing of L-Functions at the Central Point
Alexandra Florea
3:30pm|Simonyi 101 and Remote Access

In this talk, I will focus on simultaneous non-vanishing results for Dirichlet L-functions at the central point 1/2. Specifically, I will describe non-vanishing results (conditional on GRH) for two L-functions associated to Dirichlet characters in...

Dec
18
2025

Joint IAS/PU Number Theory

Euler Systems in the Twisted Friedberg-Jacquet Setting
Shilin Lai
3:30pm|Simonyi 101 and Remote Access

We construct the tame part of a split anticyclotomic Euler system in a setting where local multiplicity one does not hold. Instead of the traditional zeta integral approach, we prove the existence of the necessary test vectors using a new method...

Joint IAS/PU Number Theory Seminar

Sep
22
2022

Joint IAS/PU Number Theory Seminar

Arithmetic holonomy bounds and Apery limits
5:10pm|Simonyi Hall 101 and Remote Access

A Diophantine upper bound on the dimensions of certain spaces of holonomic functions was the main ingredient in our proof with Calegari and Tang of the 'unbounded denominators conjecture' (presented by Tang in last year's number theory seminar) from...

Sep
29
2022

Joint IAS/PU Number Theory Seminar

Higher Hida Theory
Vincent Pilloni
4:30pm|Zoom

Modular forms are degree zero cohomology of certain invertible sheaves on modular curves. One is often led to consider also higher cohomology of automorphic vector bundles on Shimura varieties. We try to define and understand the integral coherent...

Oct
06
2022

Joint IAS/PU Number Theory Seminar

New Cohen-Lenstra heuristics by constructing measures from moments
Will Sawin
4:30pm|Simonyi Hall 101 and Remote Access

The Cohen-Lenstra heuristics give predictions for the distribution of the class groups of a random quadratic number field. Cohen and Martinet generalized them to predict the distribution of the class groups of random extensions of a fixed base field...

Oct
13
2022

Joint IAS/PU Number Theory Seminar

A Visit to 3-manifolds in the Quest to Understand Random Galois Groups
Melanie Matchett Wood
5:10pm|Simonyi Hall 101 and Remote Access

Cohen, Lenstra, and Martinet gave conjectural distributions for the class group of a random number field. Since the class group is the Galois group of the maximum abelian unramified extension, a natural generalization would be to give a conjecture...

Oct
20
2022

Joint IAS/PU Number Theory Seminar

On the kernel of the non abelian Fourier transform
Ngo Bao Chau
4:30pm|Simonyi Hall 101 and Remote Access

Tate reformulated the theory of the Riemann zeta function and its functional equation as the Mellin shadow of the Fourier transform on a certain space of function on the adeles. Conjecturally, Langlands' general automorphic L-functions and their...

Oct
27
2022

Joint IAS/PU Number Theory Seminar

Class Group Actions: Measure Rigidity, L-functions and Sieving
4:30pm|Princeton University, Fine Hall 224

The linearization method of Dani-Margulis controls the amount of time a unipotent trajectory spends near invariant subvarieties of a homogeneous space. I will describe a problem in number theory where a similar control is desired for diagonalizable...

Nov
03
2022

Joint IAS/PU Number Theory Seminar

Applications of the Endoscopic Classification to Statistics of Cohomological Automorphic Representations on Unitary Groups
Rahul Dalal
4:30pm|Simonyi Hall 101 and Remote Access

Consider the family of automorphic representations on some unitary group with fixed (possibly non-tempered) cohomological representation $\pi_0$ at infinity and level dividing some finite upper bound. We compute statistics of this family as the...

Nov
10
2022

Joint IAS/PU Number Theory Seminar

Congruences Between Modular Forms and the Categorical p-adic Langlands Program
Toby Gee
4:30pm|Princeton University, Fine Hall 224

I will attempt to give a gentle introduction to the categorical p-adic Langlands program and its connections to questions about congruences between modular forms.

Nov
17
2022

Joint IAS/PU Number Theory Seminar

Toward a Theory of Prime Detecting Sieves
4:30pm|Simonyi Hall 101 and Remote Access

Given a set of integers, we wish to know how many primes there are in the set.  Modern tools allow us to obtain an asymptotic for the number of primes, or at least a lower bound of the expected order, assuming certain strength Type-I information...

Dec
01
2022

Joint IAS/PU Number Theory Seminar

Plectic Stark-Heegner Points
Michele Fornea
4:30pm|Princeton University, Fine Hall 214

I will report on a series of joint works with Gehrmann, Guitart and Masdeu about a plectic generalization of Darmon's Stark-Heegner (SH) points. 

We constructed plectic SH points as p-adic points on elliptic curves and we expect them to control the...

Dec
08
2022

Joint IAS/PU Number Theory Seminar

Quadratic Twists of Modular L-Functions
Xiannan Li
4:30pm|Simonyi Hall 101 and Remote Access

The behavior of quadratic twists of modular L-functions is at the critical point is related both to coefficients of half integer weight modular forms and data on elliptic curves.  Here we describe a proof of an asymptotic for the second moment of...

Dec
15
2022

Joint IAS/PU Number Theory Seminar

A Motivic Circle Method
4:30pm|Princeton University, Fine Hall 224

The circle method has been a versatile tool in the study of rational points on hypersurfaces. More recently, a version of the method over function fields, combined with spreading out techniques, has led to information about moduli spaces of rational...

Jan
26
2023

Joint IAS/PU Number Theory Seminar

Counting Low Degree Number Fields with Almost Prescribed Successive Minima
Sameera Vemulapalli
4:30pm|Simonyi Hall 101 and Remote Access

The successive minima of an order in a degree n number field are n real numbers encoding information about the Euclidean structure of the order. How many orders in degree n number fields are there with almost prescribed successive minima, fixed...

Feb
02
2023

Joint IAS/PU Number Theory Seminar

Selmer Averages in Families of Elliptic Curves with Marked Points and Applications
3:00pm|Princeton University, Fine Hall 214

Orbits of many coregular representations of algebraic groups are closely linked to moduli spaces of genus one curves with extra data. We may use these orbit parametrizations to compute the average size of Selmer groups of elliptic curves in certain...

Feb
03
2023

Joint IAS/PU Number Theory Seminar

Sums of Two Cubes
Ari Shnidman
2:30pm|Princeton University, Fine Hall 214

We prove that at least 2/21 of all integers can be written as a sum of two rational cubes, and at least 1/6 of all integers cannot. More generally, in any cubic twist family of elliptic curves, at least one 1/6 of curves have rank 0 and at least 1/6...

Feb
10
2023

Joint IAS/PU Number Theory Seminar

Regular de Rham Galois Representations in the Completed Cohomology of Modular Curves
Lue Pan
4:30pm|Princeton University, Fine 214

Let p be a prime. I want to explain how to use the geometry of modular curves at infinite level and the Hodge–Tate period map to study regular de Rham p-adic Galois representations appearing in the p-adically completed cohomology of modular curves...

Feb
16
2023

Joint IAS/PU Number Theory Seminar

An Euler System for the Symmetric Square of a Modular Form
Chris Skinner
4:30pm|Simonyi Hall 101 and Remote Access

I will explain a new construction of an Euler system for the symmetric square of an eigenform and its connection with L-values. The construction makes use of some simple Eisenstein cohomology classes for Sp(4) or, equivalently, SO(3,2). This is an...

Feb
23
2023

Joint IAS/PU Number Theory Seminar

Applications of the Relative Trace Formula
4:30pm|Simonyi Hall 101 and Remote Access

I discuss the spectral and arithmetic side of the relative trace formula of Kuznetsov type for congruence subgroups of SL(n, Z) with applications to automorphic density theorems. A particular focus is on properties of general Kloosterman sums as...

Mar
02
2023

Joint IAS/PU Number Theory Seminar

Fourier Interpolation and the Weil Representation
4:30pm|Princeton University, Fine Hall 214

In 2017, Radchenko-Viazovska proved a remarkable interpolation result for even Schwartz functions on the real line: such a function is entirely determined by its values and those of its Fourier transform at square roots of integers. We give a new...

Mar
09
2023

Joint IAS/PU Number Theory Seminar

Structure and Randomness in the Pro-Nilpotent Tower of Number Fields
Carlo Pagano
4:30pm|Princeton University, Fine Hall 214

I will talk about a program aimed at exploiting randomness of certain "graphs of symbols" in determining the precise structure of the pro-nilpotent Galois groups of number fields, and how this has been successfully implemented in nilpotency class 2...

Mar
23
2023

Joint IAS/PU Number Theory Seminar

The Nonvanishing of Selmer Groups for Certain Symplectic Galois Representations
Samuel Mundy
4:30pm|Princeton University, Fine Hall 214

Given an automorphic representation \pi of SO(n,n+1) with certain nice properties at infinity, one can nowadays attach to \pi a p-adic Galois representation R of dimension 2n. The Bloch--Kato conjectures then predict in particular that if the L...

Mar
30
2023

Joint IAS/PU Number Theory Seminar

Integrality of Theta Liftings to a Definite U(2)
Yu-Sheng Lee
4:30pm|Princeton University, Fine Hall 214

We discuss the integrality of theta liftings of anti-cyclotomic characters to a definite unitary group of two variables. This will allow us to construct a Hida family of the theta liftings and relate the congruence module of which to an anti...