The amenability of the universal groupoids of a Clifford semigroup

Document Type : Original Article

Authors

Department of Mathematics, University of Qom, Qom, Iran

Abstract

We show that there is a one-to-one correspondence (up to isomorphism) between maximal subgroups of a Clifford semigroup and isotropy subgroups of its universal groupoid. We prove that a Clifford semigroup is a union of amenable subgroups if and only if its universal groupoid is amenable. We give an example of an amenable Clifford semigroup that its universal groupoid is not amenable.

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