# The Dixmier-Douady classes of certain groupoid C∗-algebras with continuous trace

@article{Ionescu2018TheDC,
title={The Dixmier-Douady classes of certain groupoid C∗-algebras with continuous trace},
author={Marius Ionescu and Alex Kumjian and Aidan Sims and Dana P. Williams},
journal={Journal of Operator Theory},
year={2018}
}
• Published 2 January 2018
• Mathematics
• Journal of Operator Theory
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 Cech 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 etale equivalence relations.
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