Abstract
We show that every groupoid C*-algebra is isomorphic to its opposite, and deduce that there exist C*-algebras that are not stably isomorphic to groupoid C*-algebras, though many of them are stably isomorphic to twisted groupoid C*-algebras. We also prove that the opposite algebra of a section algebra of a Fell bundle over a groupoid is isomorphic to the section algebra of a natural opposite bundle.
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The first author is supported by CNPq (Brazil).
The second author was supported by the Australian Research Council grant DP150101598.
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Buss, A., Sims, A. Opposite algebras of groupoid C*-algebras. Isr. J. Math. 244, 759–774 (2021). https://doi.org/10.1007/s11856-021-2190-5
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DOI: https://doi.org/10.1007/s11856-021-2190-5