English

Clopen type semigroups of actions on $0$-dimensional compact spaces

Dynamical Systems 2024-10-04 v2

Abstract

We investigate some properties of the clopen type semigroup of an action of a countable group on a compact, 00-dimensional, Hausdorff space X. We discuss some characterizations of dynamical comparison (most of which were already known in the metrizable case) in this setting; and prove that for a Cantor minimal action α\alpha of an amenable group the topological full group of α\alpha admits a dense, locally finite subgroup iff the corresponding clopen type semigroup is unperforated. We also discuss some properties of clopen type semigroups of the Stone-\v{C}ech compactifications and universal minimal flows of countable groups, and derive some consequences on generic properties in the space of minimal actions of a given countable group on the Cantor space.

Keywords

Cite

@article{arxiv.2210.13203,
  title  = {Clopen type semigroups of actions on $0$-dimensional compact spaces},
  author = {Julien Melleray},
  journal= {arXiv preprint arXiv:2210.13203},
  year   = {2024}
}

Comments

updated version following a referee report

R2 v1 2026-06-28T04:21:19.270Z