ON THE CLASSIFICATION OF POINTED FUSION CATEGORIES UP TO WEAK MORITA EQUIVALENCE

A pointed fusion category is a rigid tensor category with finitely many isomorphism classes of simple objects which moreover are invertible. Two tensor categories C and D are weakly Morita equivalent if there exists an indecomposable right module category M over C such that Fun C. M; M /and D are tensor equivalent. We use the Lyndon-Hochschild-Serre spectral sequence associated to abelian group extensions to give necessary and sufficient conditions in terms of cohomology classes for two pointed fusion categories to be weakly Morita equivalent. This result allows one to classify the equivalence classes of pointed fusion categories of any given global dimension.