Morita Equivalence of Twisted Crossed Products by Coactions

We introduce a natural notion of strong Morita equivalence of twisted coactions on C*-algebras and then show that the corresponding twisted crossed product C*-algebras are strongly Morita equivalent. This is an analogue of the notion of strong Morita equivalence of Green′s twisted actions. We also present criteria for strong Morita equivalence of crossed products by coactions and produce a family of twisted coactions on a groupoid C*-algebra.