English

Weakly tracially approximately representable actions

Operator Algebras 2023-09-20 v2 Functional Analysis

Abstract

We describe a weak tracial analog of approximate representability under the name "weak tracial approximate representability" for finite group actions. Let GG be a finite abelian group, let AA be an infinite-dimensional simple unital C*-algebra, and let α ⁣:GAut(A)\alpha \colon G \to \operatorname{Aut} (A) be an action of GG on AA which is pointwise outer. Then α\alpha has the weak tracial Rokhlin property if and only if the dual action α^\widehat{\alpha} of the Pontryagin dual G^\widehat{G} on the crossed product C(G,A,α)C^*(G, A, \alpha) is weakly tracially approximately representable, and α\alpha is weakly tracially approximately representable if and only if the dual action α^\widehat{\alpha} has the weak tracial Rokhlin property. This generalizes the results of Izumi in 2004 and Phillips in 2011 on the dual actions of finite abelian groups on unital simple C*-algebras.

Keywords

Cite

@article{arxiv.2110.07081,
  title  = {Weakly tracially approximately representable actions},
  author = {M. Ali Asadi-Vasfi},
  journal= {arXiv preprint arXiv:2110.07081},
  year   = {2023}
}

Comments

20 pages, J. Operator Theory, to appear

R2 v1 2026-06-24T06:52:29.990Z