Title: 'Almost' Representations and Group Stability
Speaker: Bharatram Rangarajan (Einstein Institute of Mathematics, Hebrew University of Jerusalem, Israel)
Date: 10 January 2024
Time: 4 pm
Venue: LH-1, Mathematics Department
Consider the following natural robustness question: is an almost-homomorphism of a group necessarily a small deformation of a homomorphism?
This classical question of stability goes all the way back to Turing and Ulam, and can be posed for different target groups, and different
notions of distance. Group stability has been an active line of study in recent years, thanks to its connections to major open problems like
the existence of non-sofic and non-hyperlinear groups, the group Connes embedding problem and the recent breakthrough result MIP*=RE, apart
from property testing and error-correcting codes.
In this talk, I will survey some of the main results, techniques, and questions in this area.