##### Department of Mathematics,

University of California San Diego

****************************

### Math 211B - Group Actions Seminar

## Srivatsav Kunnawalkam Elayavalli

#### Institute for Pure and Applied Mathematics, UCLA

## Conjugacy for almost homomorphisms of sofic groups

##### Abstract:

I will discuss recent joint work with Hayes wherein we show that any sofic group G that is initially sub-amenable (a limit of amenable groups in Grigorchuk's space of marked groups) admits two embeddings into the universal sofic group S that are not conjugate by any automorphism of S. Time permitting, I will also characterise precisely when two almost homomorphisms of an amenable group G are conjugate, in terms of certain IRS's associated to the two actions of G. One of the applications of this is to recover the result of Becker-Lubotzky-Thom around permutation stability for amenable groups. The main novelty of our work is the usage of von Neumann algebraic techniques in a crucial way to obtain group theoretic consequences.

Host: Brandon Seward

### April 27, 2023

### 10:00 AM

AP&M 7218 and Zoom ID 967 4109 3409

Email an organizer for the password

Research Areas

Ergodic Theory and Dynamical Systems****************************