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Continuous spectral decompositions of Abelian group actions on C*-algebras

Alcides Buss·Ralf Meyer
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Abstract

Let G be a locally compact Abelian group. Following Ruy Exel, we view Fell bundles over the Pontrjagin dual of G as continuous spectral decompositions of G-actions on C*-algebras. We classify such spectral decompositions using certain dense subspaces related to Marc Rieffel's theory of square-integrability. There is a unique continuous spectral decomposition if the group acts properly on the primitive ideal space of the C*-algebra. But there are also examples of group actions without or with several inequivalent spectral decompositions.

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Alcides Buss, Ralf Meyer. 2007-03-10. Continuous spectral decompositions of Abelian group actions on C*-algebras. https://doi.org/10.1016/j.jfa.2007.04.009

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