Hostname: page-component-74656f9884-npj9w Total loading time: 0 Render date: 2026-11-10T05:20:31.726Z Has data issue: false hasContentIssue false

Harmonic inverse semigroups

Published online by Cambridge University Press:  18 May 2009

Mario Petrich
Affiliation:
University of Western Ontario, London, Canada
Stuart A. Rankin
Affiliation:
University of Western Ontario, London, Canada
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

An inverse semigroup S shall be said to be harmonic if every congruence on S is determined by any one of its classes. In other words, if λ and ρ are congruences on S having a congruence class in common, then λ = ρ. The class of all harmonic semigroups contains all bisimple inverse semigroups, as proved by Žitomirskiĭ [11] and also by Schein [10], and all congruence-free inverse semigroups. Moreover, is contained in the class of all 0-simple or simple inverse semigroups, as is easy to see. We shall show that there exist non-bisimple, non-congruence-free harmonic semigroups and that there are simple inverse semigroups which are not harmonic.

Information

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1989