Skew products and crossed products by coactions

dc.creatorKaliszewski, S.
dc.creatorQuigg, John
dc.creatorRaeburn, Iain
dc.date1999-01-22
dc.date.accessioned2026-07-07T05:27:38Z
dc.date.available2026-07-07T05:27:38Z
dc.descriptionGiven a labeling c of the edges of a directed graph E by elements of a discrete group G, one can form a skew-product graph E cross_c G. We show, using the universal properties of the various constructions involved, that there is a coaction delta of G on C*(E) such that C*(E cross_c G) is isomorphic to the crossed product C*(E) cross_delta G. This isomorphism is equivariant for the dual action deltahat and a natural action gamma of G on C*(E cross_c G); following results of Kumjian and Pask, we show that C*(E cross_c G) cross_gamma G is isomorphic to C*(E cross_c G) cross_{gamma,r} G, which in turn is isomorphic to C*(E) tensor K(l^2(G)), and it turns out that the action gamma is always amenable. We also obtain corresponding results for r-discrete groupoids Q and continuous homomorphisms c: Q -> G, provided Q is amenable. Some of these hold under a more general technical condition which obtains whenever Q is amenable or second-countable.
dc.description22 pages, LaTeX2e, uses pb-diagram.sty
dc.identifierhttps://arxiv.org/abs/math/9901101
dc.identifierhttp://arxiv.org/abs/math/9901101
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/77991
dc.subjectOperator Algebras
dc.subject46L55
dc.titleSkew products and crossed products by coactions
dc.typetext

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