Galois Extensions for Co-Frobenius Hopf Algebras

Abstract

ForHan infinite dimensional co-Frobenius Hopf algebra over a fieldk, andAanH-comodule algebra, the smash productA#H*ratis linked to the ring of coinvariantsAcoHby a Morita context. We use the Morita setting to show that for co-FrobeniusH, equivalent conditions forA/AcoHto be Galois parallel the case ofHfinite dimensional.