A topological correspondence between partial actions of groups and inverse semigroup actions

Abstract

We present some generalizations of the well-known correspondence, found by R. Exel, between partial actions of a group $G$ on a set $X$ and semigroup homomorphism of $S(G)$ on the semigroup $I(X)$ of partial bijections of $X,$ being $S(G)$ an inverse monoid introduced by Exel. We show that any unital premorphism $\theta :G\to S$, where $S$ is an inverse monoid, can be extended to a semigroup homomorphism ${\theta }^{\ast }:T\to S$ for any inverse semigroup $T$ with $S(G)\subseteq T\subseteq P^{\ast }(G)\times G,$ being $P^{\ast }(G)$ the semigroup of non-empty subset of $G$, and such that $E(S)$ satisfies some lattice theoretical condition. We also consider a topological version of this result. We present a minimal Hausdorff inverse semigroup topology on $\Gamma (X)$, the inverse semigroup of partial homeomorphism between open subsets of a locally compact Hausdorff space $X$.