HOPF-JACOBSON RADICAL FOR COMODULE ALGEBRAS

Abstract

Let H be a Hopf algebra over a field k (not necessarily finite dimensional). In this paper the Hopf-Jacobson radical JH(A) of right H-comodule algebra A (not necessarily with identity) is studied. The relationships between JH(A) and the Jacobson radical of the smash product A#H*rat are discussed. The density theorem is given for left (A,H)-Hopf simple module.