Normal Smash Products

  title={Normal Smash Products},
  author={Sung-Dae Yang and Defeng Wang}
Let H be a co-Frobenius Hopf algebra over a field k and A a right H-comodule algebra. It is shown that A is H-faithful and AN #N ∗ ∈ Φ iff A#H ∈ Φ, where N is a subgroup of G(H) = {g ∈ H | ∆(g) = g ⊗ g} and AN is N -coinvariants, Φ denotes a normal class. It is also shown that if A/A1 is right H-Galois and A1 is central simple, then so is A#H. In particular… CONTINUE READING