English

Approximate homomorphisms and sofic approximations of orbit equivalence relations

Group Theory 2024-11-20 v2 Dynamical Systems Operator Algebras

Abstract

We show that for every countable group, any sequence of approximate homomorphisms with values in permutations can be realized as the restriction of a sofic approximation of an orbit equivalence relation. Moreover, this orbit equivalence relation is uniquely determined by the invariant random subgroup of the approximate homomorphism. We record applications of this result to recover various known stability and conjugacy characterizations for almost homomorphisms of amenable groups.

Keywords

Cite

@article{arxiv.2306.16974,
  title  = {Approximate homomorphisms and sofic approximations of orbit equivalence relations},
  author = {Ben Hayes and Srivatsav Kunnawalkam Elayavalli},
  journal= {arXiv preprint arXiv:2306.16974},
  year   = {2024}
}

Comments

22 pages, no figures. To appear in Ergodic Theory and Dynamical Systems

R2 v1 2026-06-28T11:17:58.610Z