右(D,B)-Doi-Hopf模范畴上的扭曲

Twist of the Category of Right (D,B)-Doi-Hopf Modules

设k是交换环,A是k上的双代数,D是右A-模余代数,B是右A-余模代数。在D上定义新的余乘法,得到一个“扭曲的余代数”Dτ,给出Dτ是A-模余代数的充要条件。类似的定义了左扭曲,并讨论了类似的性质。

For k a commutative ring,A a k-bialgebra and D a right A-comodule k-algebra,we define a new comultiplication on the A-comodule D to obtain a “twisted coalgebra”D~τ,and give the sufficient and necessary conditions for D~τbeing a A-module coalgebra.