2019/11/18 by Kodaka, Kazunori
#46L05 #FOS: Mathematics #Operator Algebras (math.OA)
paper · doi:10.48550/arxiv.1911.07477
Let A and B be σ-unital C^*-algebras and X and Y an A-A-equivalence bimodule and a B-B-equivalence bimodule, respectively. Also, let A\rtimesX ℤ and B\rtimesY ℤ be the crossed products of A and B by X and Y, respectively. Furthermore, let A⊂ A\rtimesX ℤ and B⊂ B\rtimesY ℤ be the inclusions of C^*-algebras induced by X and Y, respectively. We suppose that A' ∩ M(A\rtimesX ℤ)=ℂ 1. In this paper we shall show that the inclusions A⊂ A\rtimesX ℤ and B⊂ B\rtimesY ℤ are strongly Morita equivalent if and only if there is an A-B-equivalence bimodule M such that Y≅ \widetildeM⊗A X ⊗A M or \widetildeY≅ \widetildeM⊗A X ⊗A M as B-B-equivalence bimodules, where \widetildeM and \widetildeY are the dual B-A-equivalence bimodule and the dual B-B-equivalence bimodule of M and Y, respectively. Applying this result, we shall compute the Picard group of the inclusion A⊂ A\rtimesX ℤ under the assumption that A' ∩ M(A\rtimesX ℤ)=ℂ 1.