REALIZATION OF BIG CENTRALIZERS OF MINIMAL APERIODIC ACTIONS ON THE CANTOR SET

In this article we study the centralizer of a minimal aperiodic action of a countable group on the Cantor set (an aperiodic minimal Cantor system). We show that any countable residually finite group is the subgroup of the centralizer of some minimal Z action on the Cantor set, and that any countable group is the subgroup of the normalizer of a minimal aperiodic action of an abelian countable free group on the Cantor set. On the other hand we show that for any countable group G, the centralizer of any minimal aperiodic G-action on the Cantor set is a subgroup of the centralizer of a minimal Z-action.