On partial representations of pointed Hopf algebras

Abstract

Partial representations of Hopf algebras were motivated by the theory of partial representations of groups. Alves, Batista e Vercruysse introduced partial representations of a Hopf algebra and showed that, as in the case of partial groups actions, a partial $H$-action on an algebra $A$ leads to a partial representation on the algebra of linear endomorphisms of $A$, and a left module $M$ over the partial smash product of $A$ by $H$ carries also a partial representation of $H$ on its algebra of linear endomorphisms. Moreover, partial representations of $H$ correspond to left modules over a Hopf algebroid $H_{par}$. It is known from a result by Dokuchaev, Exel and Piccione that when $H$ is the algebra of a finite group $G$, then $H_{par}$ is isomorphic to the algebra of a finite groupoid determined by $G$. In this work we show that if $H$ is a pointed Hopf algebra with finite group $G$ of grouplikes then $H_{par}$ can be written as a direct sum of unital ideals indexed by the components of the same groupoid associated to the group $G$.