Almost finiteness and groups of dynamical origin
Dynamical Systems
2025-01-20 v5 Operator Algebras
Abstract
We introduce the property of having good subgroups for actions of countable discrete groups on compact metrizable spaces, and show that it implies comparison when the acting group is amenable. As a consequence, free actions on finite-dimensional spaces of many notable amenable groups of dynamical origin are almost finite. For instance, this applies to topological full groups of Cantor minimal systems and the Basilica group. In particular, minimal such actions give rise to classifiable crossed products.
Cite
@article{arxiv.2401.06006,
title = {Almost finiteness and groups of dynamical origin},
author = {Petr Naryshkin and Spyridon Petrakos},
journal= {arXiv preprint arXiv:2401.06006},
year = {2025}
}
Comments
10 pages; to be published in Int. Math. Res. Not. IMRN; major changes, non-amenable part split into separate paper