External Homogenization for Hopf Algebras:Applications to Maschke's Theorem

摘要

We apply to Hopf algebras a construction from graded rings, called "the group ring of a graded ring". By using this construction we study the transfer of properties between certain categories of relative Hopf modules. As another application, we obtain a Maschke-type theorem for a Galois extension over a semisimple Hopf algebra.