English

$C^*$-simplicity and representations of topological full groups of groupoids

Operator Algebras 2020-11-09 v2 Group Theory

Abstract

Given an ample groupoid GG with compact unit space, we study the canonical representation of the topological full group [[G]][[G]] in the full groupoid CC^*-algebra C(G)C^*(G). In particular, we show that the image of this representation generates C(G)C^*(G) if and only if C(G)C^*(G) admits no tracial state. The techniques that we use include the notion of groups covering groupoids. As an application, we provide sufficient conditions for CC^*-simplicity of certain topological full groups, including those associated with topologically free and minimal actions of non-amenable and countable groups on the Cantor set.

Keywords

Cite

@article{arxiv.1805.06743,
  title  = {$C^*$-simplicity and representations of topological full groups of groupoids},
  author = {Kevin Aguyar Brix and Eduardo Scarparo},
  journal= {arXiv preprint arXiv:1805.06743},
  year   = {2020}
}

Comments

13 pages. Minor changes, including new references. Accepted in Journal of Functional Analysis