English

The polycyclic inverse monoids and the Thompson groups revisited

Group Theory 2020-06-30 v1

Abstract

We revisit our construction of the Thompson groups from the polycyclic inverse monoids in the light of new research. Specifically, we prove that the Thompson group Gn,1G_{n,1} is the group of units of a Boolean inverse monoid CnC_{n} called the Cuntz inverse monoid. This inverse monoid is proved to be the tight completion of the polycyclic inverse monoid PnP_{n}. The \'etale topological groupoid associated with CnC_{n} under non-commutative Stone duality is the usual groupoid associated with the corresponding Cuntz CC^{\ast}-algebra. We then show that the group Gn,1G_{n,1} is also the group of automorphisms of a specific nn-ary Cantor algebra: this nn-ary Cantor algebra is constructed first as the monoid of total maps of a restriction semigroup \`a la Statman and then in terms of labelled trees \`a la Higman.

Keywords

Cite

@article{arxiv.2006.15338,
  title  = {The polycyclic inverse monoids and the Thompson groups revisited},
  author = {Mark V Lawson},
  journal= {arXiv preprint arXiv:2006.15338},
  year   = {2020}
}