English

The local bisection hypothesis for twisted groupoid C*-algebras

Operator Algebras 2023-10-24 v2 Rings and Algebras

Abstract

In this note, we present criteria that are equivalent to a locally compact Hausdorff groupoid GG being effective. One of these conditions is that GG satisfies the "C*-algebraic local bisection hypothesis"; that is, that every normaliser in the reduced twisted groupoid C*-algebra is supported on an open bisection. The semigroup of normalisers plays a fundamental role in our proof, as does the semigroup of normalisers in cyclic group C*-algebras.

Keywords

Cite

@article{arxiv.2307.13814,
  title  = {The local bisection hypothesis for twisted groupoid C*-algebras},
  author = {Becky Armstrong and Jonathan H. Brown and Lisa Orloff Clark and Kristin Courtney and Ying-Fen Lin and Kathryn McCormick and Jacqui Ramagge},
  journal= {arXiv preprint arXiv:2307.13814},
  year   = {2023}
}

Comments

11 pages. This version matches the version in Semigroup Forum

R2 v1 2026-06-28T11:40:06.946Z