Crossed products and twisted k-graph algebras

An automorphism β of a k-graph Λ induces a crossed product C⋆(Λ)⋊βZ which is isomorphic to a (k+1)-graph algebra C⋆(ΛxβZ). In this paper we show how this process interacts with k-graph C⋆- algebras which have been twisted by an element of their second co-homology group. This analysis is done using a long exact sequence in cohomology associated to this data. We conclude with some examples.