Classifiability of crossed products by nonamenable groups
Operator Algebras
2023-03-01 v3 Dynamical Systems
Abstract
We show that all amenable, minimal actions of a large class of nonamenable countable groups on compact metric spaces have dynamical comparison. This class includes all nonamenable hyperbolic groups, many HNN-extensions, nonamenable Baumslag-Solitar groups, a large class of amalgamated free products, lattices in many Lie groups, -groups, as well as direct products of the above with arbitrary countable groups. As a consequence, crossed products by amenable, minimal and topologically free actions of such groups on compact metric spaces are Kirchberg algebras in the UCT class, and are therefore classified by -theory.
Keywords
Cite
@article{arxiv.2201.03409,
title = {Classifiability of crossed products by nonamenable groups},
author = {Eusebio Gardella and Shirly Geffen and Julian Kranz and Petr Naryshkin},
journal= {arXiv preprint arXiv:2201.03409},
year = {2023}
}
Comments
v2: 30 pages, 1 figure. To appear in J. Reine Angew. Math. (Crelle)