# Seminar 10.28.21 Sun

Title: Joint ergodicity conjecture for systems with commuting transformations

Speaker: Wenbo Sun – Virginia Tech

Abstract: It is well know by the Mean Ergodic Theorem that for any measure preserving system $(X,\mathcal{B},\mu,T)$ and $L^{\infty}$ function f, the time average of $T^{n}f$ converges to the integral of f if and only if T is ergodic. It is a natural question to ask when the average of products of polynomial iterates of  $L^{\infty}$ functions (known as multiple ergodic averages) converges to the product of the integrals of the functions. This question is called the Joint Ergodicity Problem. In this talk, I will introduce some recent advances in this problem. This talk is based on joint works with Sebasti\’an Donoso, Andreu Ferr\’e Moragues and Andreas Koutsogiannis.