Previous Special Year Seminar

Mar
22
2023

Special Year Learning Seminar

Sets of Multiplicative Recurrence
10:30am|Simonyi 101 and Remote Access

Sets of recurrence were introduced by Furstenberg in the context of ergodic theory and have an equivalent combinatorial characterization as intersective sets, an observation which has led to interesting connections between these areas.

Originally...

Mar
21
2023

Special Year Research Seminar

Unbounded Fast Escaping Wandering Domains
Adi Glücksam
2:00pm|Simonyi 101 and Remote Access

Complex dynamics explores the evolution of points under iteration of functions of complex variables. In this talk I will introduce into the context of complex dynamics, a new approximation tool allowing us to construct new examples of entire...

Mar
14
2023

Special Year Research Seminar

Geometric Representation of Structured Extensions in Ergodic Theory
Henrik Kreidler
2:00pm|Simonyi 101 and Remote Access

The Mackey-Zimmer representation theorem is a key structural result from ergodic theory: Every compact extension between ergodic measure-preserving systems can be written as a skew-product by a homogeneous space of a compact group. This is used, e.g...

Mar
10
2023

Special Year Informal Seminar

A Non-flag Arithmetic Regularity Lemma and Counting Lemma
Daniel Altman
1:30pm|Simonyi 101

We will discuss a version of the Green--Tao arithmetic regularity lemma and counting lemma which works in the generality of all linear forms. In this talk we will focus on the qualitative and algebraic aspects of the result.

Mar
07
2023

Special Year Research Seminar

Some Inverse Theorems in Ergodic Theory and Additive Combinatorics
3:30pm|Simonyi 101 and Remote Access

The Gowers uniformity k-norm on a finite abelian group measures the averages of complex functions on such groups over k-dimensional arithmetic cubes. The inverse question about these norms asks if a large norm implies correlation with a function of...

Mar
07
2023

Special Year Research Seminar

Homogeneous Structures in Subset Sums and Non-averaging Sets
David Conlon
2:00pm|Simonyi 101 and Remote Access

We show that for every positive integer k there are positive constants C and c such that if A is a subset of {1, 2, ..., n} of size at least C n^{1/k}, then, for some d \leq k-1, the set of subset sums of A contains a homogeneous d-dimensional...

Mar
06
2023

Special Year Informal Seminar

Degree Lowering Along Arithmetic Progressions
Borys Kuca
9:30am|Simonyi 101

Ever since Furstenberg proved his multiple recurrence theorem, the limiting behaviour of multiple ergodic averages along various sequences has been an important area of investigation in ergodic theory. In this talk, I will discuss averages along...

Feb
22
2023

Special Year Learning Seminar

Automorphic Density Theorems
10:30am|Simonyi 101 and Remote Access

A density theorem for L-functions is quantitative measure of the possible failure of the Riemann Hypothesis. In his 1990 ICM talk, Sarnak introduced the notion of density theorems for families of automorphic forms, measuring the possible failure of...

Feb
21
2023

Special Year Research Seminar

Restriction of Exponential Sums to Hypersurfaces
2:00pm|Simonyi 101 and Remote Access

The last decade has witnessed a revolution in the circle of problems concerned with proving sharp moment inequalities for exponential sums on tori. This has in turn led to a better understanding of pointwise estimates, but this topic remains...

Feb
15
2023

Special Year Learning Seminar

Strong Stationarity and Multiplicative Functions
10:30am|Simonyi 101 and Remote Access

The notion of strong stationarity was introduced by Furstenberg and Katznelson in the early 90's in order to facilitate the proof of the density Hales-Jewett theorem. It has recently surfaced that this strong statistical property is shared by...