English

Stable and real rank for crossed products by finite groups

Operator Algebras 2023-11-21 v1

Abstract

A long-standing open question in the theory of group actions on C*-algebras is the stable rank of the crossed product. Specifically, N. C. Phillips asked that if a finite group GG acts on a simple unital C*-algebra AA with stable rank one, does the crossed product have stable rank one? A similar question can be asked about the real rank. Most of the existing partial answers contain a reasonable restriction (mainly, a Rokhlin-type property) on the action and assumptions on AA. We remove all extra assumptions on AA (for instance, stable finiteness and that the order on projections over AA is determined by traces) and we prove that if the action has the tracial Rokhlin property and AA is simple and σ\sigma-unital with stable rank one or real rank zero, then so do the crossed product and the fixed point algebra. Moreover, we show that if the Kirchberg's central sequence algebra F(A)\mathrm{F}(A) has real rank zero, then the weak tracial Rokhlin property is equivalent to the tracial Rokhlin property for actions on simple unital separable C*-algebras AA.

Keywords

Cite

@article{arxiv.2311.11746,
  title  = {Stable and real rank for crossed products by finite groups},
  author = {Parisa Elyasi and Nasser Golestani},
  journal= {arXiv preprint arXiv:2311.11746},
  year   = {2023}
}

Comments

17 pages. arXiv admin note: text overlap with arXiv:1711.10818