The Dixmier-Douady Classes of Certain Groupoid C*-Algebras with Continuous Trace

الأصل · EN

Given a locally compact abelian group G, we give an explicit formula for the Dixmier--Douady invariant of the C*-algebra of the groupoid extension associated to a Čech 2-cocycle in the sheaf of germs of continuous G-valued functions. We then exploit the blow-up construction for groupoids to extend this to some more general central extensions of étale equivalence relations.