Dynamical twists in Hopf algebras

Abstract

We establish a bijective correspondence between gauge equivalence classes of dynamical twists in a finite-dimensional Hopf algebra $H$ based on a finite abelian group $A$ and equivalence classes of pairs $(K, \{V_{\lambda}\}_{\lambda\in \hat{A}})$, where $K$ is an $H$-simple left $H$-comodule semisimple algebra and $\{V_{\lambda}\}_{\lambda\in \hat{A}}$ is a family of irreducible representations satisfying certain conditions. Our results generalize the results obtained by Etingof-Nikshych on the classification of dynamical twists in group algebras.