We gratefully acknowledge support from
the Simons Foundation and member institutions.
Full-text links:

Download:

Current browse context:

math.OA

Change to browse by:

References & Citations

Bookmark

(what is this?)
CiteULike logo BibSonomy logo Mendeley logo del.icio.us logo Digg logo Reddit logo

Mathematics > Operator Algebras

Title: Minimal compact group actions on C$^*$-algebras with simple fixed point algebras

Authors: Masaki Izumi
Abstract: The notion of qausi-product actions of a compact group on a C$^*$-algebra was introduced by Bratteli et al. in their attempt to seek an equivariant analogue of Glimm's characterization of non-type I C$^*$-algebras. We show that a faithful minimal action of a second countable compact group on a separable C$^*$-algebra is quasi-product whenever its fixed point algebra is simple. This was previously known only for compact abelian groups and for profinite groups. Our proof relies on a subfactor technique applied to finite index inclusions of simple C$^*$-algebras in the purely infinite case, and also uses ergodic actions of compact groups in the general case. As an application, we show that if moreover the fixed point algebra is a Kirchberg algebra, such an action is always isometrically shift-absorbing, and hence is classifiable by the equivariant KK-theory due to a recent result of Gabe-Szab\'o.
Comments: 34 pages
Subjects: Operator Algebras (math.OA)
Cite as: arXiv:2405.03231 [math.OA]
  (or arXiv:2405.03231v1 [math.OA] for this version)

Submission history

From: Masaki Izumi [view email]
[v1] Mon, 6 May 2024 07:42:06 GMT (29kb)

Link back to: arXiv, form interface, contact.