English

Finitely presented inverse semigroups with finitely many idempotents in each $\mathcal D$-class and non-Hausdorff universal groupoids

Group Theory 2022-07-25 v1 Operator Algebras Rings and Algebras

Abstract

The complex algebra of an inverse semigroup with finitely many idempotents in each D\mathcal D-class is stably finite by a result of Munn. This can be proved fairly easily using CC^*-algebras for inverse semigroups satisfying this condition that have a Hausdorff universal groupoid, or more generally for direct limits of inverse semigroups satisfying this condition and having Hausdorff universal groupoids. It is not difficult to see that a finitely presented inverse semigroup with a non-Hausdorff universal groupoid cannot be a direct limit of inverse semigroups with Hausdorff universal groupoids. We construct here countably many non-isomorphic finitely presented inverse semigroups with finitely many idempotents in each D\mathcal D-class and non-Hausdorff universal groupoids. At this time there is not a clear CC^*-algebraic technique to prove these inverse semigroups have stably finite complex algebras.

Keywords

Cite

@article{arxiv.2207.11206,
  title  = {Finitely presented inverse semigroups with finitely many idempotents in each $\mathcal D$-class and non-Hausdorff universal groupoids},
  author = {Pedro V. Silva and Benjamin Steinberg},
  journal= {arXiv preprint arXiv:2207.11206},
  year   = {2022}
}