Operator algebras conference in memory of Étienne Blanchard

Groupoid extensions, group bundles and weights

Apr 8, 2019, 9:00 AM

50m

Bâtiment Sophie Germain, Amphi Turing (Université Paris Diderot)

Abstract

Speaker

Jean Renault (Univ. Orléans)

Description

We give a groupoid version of Mackey normal subgroup analysis in a C-algebraic framework. More precisely, we describe the C-algebra of a groupoid which is an extension by a group bundle. When the group bundle is abelian, one obtains a twisted groupoid C-algebra. C-bundles and the canonical weight of a group bundle play a crucial role in this study. This is joint work with M. Ionescu, A. Kumjian, A. Sims and D. Williams.