English

A Classic Morita Equivalence Result for Fell Bundle C*-algebras

Operator Algebras 2010-05-11 v2 Functional Analysis

Abstract

We show how to extend a classic Morita Equivalence Result of Green's to the \cs-algebras of Fell bundles over transitive groupoids. Specifically, we show that if p:\BGp:\B\to G is a saturated Fell bundle over a transitive groupoid GG with stability group H=G(u)H=G(u) at u\gou\in \go, then \cs(G,\B)\cs(G,\B) is Morita equivalent to \cs(H,\CC)\cs(H,\CC), where \CC=\B\restrH\CC=\B\restr H. As an application, we show that if p:\BGp:\B\to G is a Fell bundle over a group GG and if there is a continuous GG-equivariant map σ:\PrimAG/H\sigma:\Prim A\to G/H, where A=B(e)A=B(e) is the \cs-algebra of \B\B and HH is a closed subgroup, then \cs(G,\B)\cs(G,\B) is Morita equivalent to \cs(H,\CCI)\cs(H,\CC^{I}) where \CCI\CC^{I} is a Fell bundle over HH whose fibres are A/I\smeA/IA/I\sme A/I-\ib s and I={P:σ(P)=eH}I=\bigcap\set{P:\sigma(P)=eH}. Green's result is a special case of our application to bundles over groups.

Keywords

Cite

@article{arxiv.0912.1125,
  title  = {A Classic Morita Equivalence Result for Fell Bundle C*-algebras},
  author = {Marius Ionescu and Dana P. Williams},
  journal= {arXiv preprint arXiv:0912.1125},
  year   = {2010}
}

Comments

10 Pages. Paper has been slightly reorganized and reformatted to appear in Math. Scand.