Title

COHOMOLOGICAL OBSTRUCTIONS TO GROUP STABILITY WITH RESPECT TO THE OPERATOR NORM.

Authors

DADARLAT, MARIUS

Abstract

In this article, we survey recent results concerning non-stability of discrete groups with respect to the operator norm. We focus on topological obstructions to perturbing almost representations of a discrete group r into unitary groups U(n) to true representations. Several natural notions of stability are discussed: local-to-local stability, uniform-to-uniform stability, uniform-to-local stability, and C * -stability.

Subjects

UNITARY groups; DISCRETE groups; K-theory

Publication

Romanian Journal of Pure & Applied Mathematics / Revue Roumaine de Mathematiques Pures et Appliquees, 2024, Vol 69, Issue 3/4, p471

ISSN

0035-3965

Publication type

Academic Journal

DOI

10.59277/RRMPA.2024.471.485