代数A在子代数A^H上投射的若干充分条件(英文)

SOME SUFFICIENT CONDITIONS THAT A ALGEBRA A OVER THE SUBALGEBRA A^H IS TO BE PROJECTIVE

假设Ｈ 是域ｋ 上的有限维Ｈｏｐｆ代数，Ａ是Ｈ－模代数。本文刻画了ＡＨＡ的投射性并给出了ＡＨＡ是投射的若干充分条件，其中ＡＨ 是Ａ的Ｈ－不变子代数。

Suppose H is a finite dimensional Hopf algebra over a field k and A an H module algebra.In this paper, we characterize the projectivity of A as a left A H module and give some easier checking sufficient conditions that A H A is projective, where A H is the subalgebra of H invariants of A .