JournalszaaVol. 16, No. 4pp. 831–850

On Conditional Expectations Arising from Group Actions

  • Michael Frank

    Hochschule für Technik, Wirtschaft und Kultur, Leipzig, Germany
  • V.M. Manuilov

    Moscow State University, Russian Federation
  • E.V. Troitsky

    Moscow State University, Russian Federation
On Conditional Expectations Arising from Group Actions cover
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Abstract

Induced conditional expectations of finite index on crossed product CC*-algebras are considered which are non-algebraically of finite index. The characteristics of actions of (amenable) topological groups on compact Hausdorff spaces XX are investigated, ensuring the appearance of a well-defined induced conditional expectation on the corresponding commutative CC*-a1gebra C(X)C(X) and its property to be of finite index. For this purpose Hilbert CC*-module and topological techniques are used. Special emphasis is placed on discrete group actions.

Cite this article

Michael Frank, V.M. Manuilov, E.V. Troitsky, On Conditional Expectations Arising from Group Actions. Z. Anal. Anwend. 16 (1997), no. 4, pp. 831–850

DOI 10.4171/ZAA/794