7 papers
Central twisted transformation groups and group -algebras of central group extensions
Siegfried Echterhoff, Dana P. Williams
We examine the structure of central twisted transformation group \cs-algebras $C_{0}(X)\rtimes_{\id,u}G$, and apply our results to the group \cs-algebras of central group extension…
A Categorical Approach to Imprimitivity Theorems for C*-Dynamical Systems
Siegfried Echterhoff, S. Kaliszewski, John Quigg +1
Imprimitivity theorems provide a fundamental tool for studying the representation theory and structure of crossed-product C*-algebras. In this work, we show that the Imprimitivity…
The Connes-Kasparov conjecture for almost connected groups
Jerome Chabert, Siegfried Echterhoff, Ryszard Nest
Let be a locally compact group with cocompact connected component. We prove that the assembly map from the topological $\k$-theory of to the $\k$-theory of the reduced $C^*…
Full duality for coactions of discrete groups
Siegfried Echterhoff, John Quigg
Using the strong relation between coactions of a discrete group G on C*-algebras and Fell bundles over G, we prove a new version of Mansfield's imprimitivity theorem for coactions…
Maximal Coactions
Siegfried Echterhoff, S. Kaliszewski, John Quigg
A coaction d of a locally compact group G on a C*-algebra A is maximal if a certain natural map from A times_d G times_{d hat} G onto A otimes K(L^2(G)) is an isomorphism. All dual…
Naturality and Induced Representations
Siegfried Echterhoff, S. Kaliszewski, John Quigg +1
We show that induction of covariant representations for C*-dynamical systems is natural in the sense that it gives a natural transformation between certain crossed-product functors…