Crossed product tensor categories

A graded tensor category over a group G will be called a crossed product tensor category if every homogeneous component has at least one multiplicatively invertible object. Our main result is a description of crossed product tensor categories, graded monoidal functors, monoidal natural transformations, and braidings in terms of coherent outer G-actions over tensor categories. (C) 2011 Elsevier Inc. All rights reserved.