Crossed products of k-graph C*-algebras by Zl

An action of Zl by automorphisms of a k-graph induces an action of Zl by automorphisms of the corresponding k-graph C*-algebra. We show how to construct a (k + l)-graph whose C*-algebra coincides with the crossed product of the original k-graph C)-algebra by Zl. We then investigate the structure of the crossed-product C*-algebra.