English

Strict comparison for $C^*$-algebras arising from Almost finite groupoids

Operator Algebras 2020-03-05 v2

Abstract

In this paper we show that for an almost finite minimal ample groupoid GG, its reduced C\mathrm{C}^*-algebra Cr(G)C_r^*(G) has real rank zero and strict comparison even though Cr(G)C_r^*(G) may not be nuclear in general. Moreover, if we further assume GG being also second countable and non-elementary, then its Cuntz semigroup Cu(Cr(G)){\rm Cu}(C_r^*(G)) is almost divisible and Cu(Cr(G)){\rm Cu}(C_r^*(G)) and Cu(Cr(G)Z){\rm Cu}(C_r^*(G)\otimes \mathcal{Z}) are canonically order-isomorphic, where Z\mathcal{Z} denotes the Jiang-Su algebra.

Keywords

Cite

@article{arxiv.2002.12221,
  title  = {Strict comparison for $C^*$-algebras arising from Almost finite groupoids},
  author = {Pere Ara and Christian Bönicke and Joan Bosa and Kang Li},
  journal= {arXiv preprint arXiv:2002.12221},
  year   = {2020}
}
R2 v1 2026-06-23T13:56:23.276Z