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arXiv · 2407.05024

Cartan semigroups and twisted groupoid C*-algebras

Tristan Bice·Lisa Orloff Clark·Ying-Fen Lin·Kathryn McCormick
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Abstract

We prove that twisted groupoid C*-algebras are characterised, up to isomorphism, by having Cartan semigroups, a natural generalisation of normaliser semigroups of Cartan subalgebras. This extends the classic Kumjian-Renault theory to general twisted \'etale groupoid C*-algebras, even non-reduced C*-algebras of non-effective groupoids.

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Tristan Bice, Lisa Orloff Clark, Ying-Fen Lin, Kathryn McCormick. 2024-07-06. Cartan semigroups and twisted groupoid C*-algebras. https://arxiv.org/abs/2407.05024

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