English
Related papers

Related papers: Inverse subsemigroups of finite index in finitely …

200 papers

We study the structure of inverse primitive feebly compact semitopological and topological semigroups. We find conditions when the maximal subgroup of an inverse primitive feebly compact semitopological semigroup $S$ is a closed subset of…

Group Theory · Mathematics 2015-10-28 Oleg Gutik , Oleksandr Ravsky

We prove that the structure of right generalized inverse semigroups is determined by free \'etale actions of inverse semigroups. This leads to a tensor product interpretation of Yamada's classical struture theorem for generalized inverse…

Category Theory · Mathematics 2012-07-19 Ganna Kudryavtseva , Mark V. Lawson

As an appropriate generalisation of the features of the classical (Schein) theory of representations of inverse semigroups in $\mathscr{I}_{X}$, a theory of representations of inverse semigroups by homomorphisms into complete atomistic…

Group Theory · Mathematics 2021-02-22 D. G. FitzGerald

We introduce the notion of semigroup with a tight ideal series and investigate their closures in semitopological semigroups, particularly inverse semigroups with continuous inversion. As a corollary we show that the symmetric inverse…

Group Theory · Mathematics 2009-03-19 Oleg Gutik , Jimmie Lawson , Dušan Repovš

In this short note, we show that the number of monogenic submonoids of the full transformation monoid of degree $n$ for $n > 0$, equals the sum of the number of cyclic subgroups of the symmetric groups on $1$ to $n$ points. We also prove an…

Group Theory · Mathematics 2023-05-15 L. Elliott , A. Levine , J. D. Mitchell

This paper introduces a notion of presentation for locally inverse semigroups and develops a graph structure to describe the elements of locally inverse semigroups given by these presentations. These graphs will have a role similar to the…

Group Theory · Mathematics 2021-12-22 Luís Oliveira

This is an account of the theory of inverse semigroups, assuming only that the reader knows the basics of semigroup theory.

Category Theory · Mathematics 2023-06-27 Mark V. Lawson

An inverse Clifford semigroup (often referred to as just a Clifford semigroup) is a semilattice of groups. It is an inverse semigroup and in fact, one of the earliest studied classes of semigroups. In this short note, we discuss various…

Group Theory · Mathematics 2022-08-02 P. A. Azeef Muhammed , C. S. Preenu

Locally inverse semigroups are regular semigroups whose idempotents form pseudo-semilattices. We characterise the categories that correspond to locally inverse semigroups in the realm of Nambooripad's cross-connection theory. Further, we…

Group Theory · Mathematics 2021-10-19 P. A. Azeef Muhammed , M. V. Volkov , K. Auinger

An inverse monoid $S$ is called $F$-inverse if each $\sigma$-class of $S$, where $\sigma$ is the minimum group congruence of $S$, has a maximum element with respect to the natural order of $S$. Since the property of an inverse monoid being…

Group Theory · Mathematics 2026-03-10 Igor Dolinka , Ganna Kudryavtseva

Graph inverse semigroups generalize the polycyclic inverse monoids and play an important role in the theory of C*-algebras. This paper has two main goals: first, to provide an abstract characterization of graph inverse semigroups; and…

Category Theory · Mathematics 2013-08-14 David G. Jones , Mark V. Lawson

Bochner's theorem characterizes positive definite functions on groups through the positivity of their Fourier transforms and plays a fundamental role in Harmonic analysis. While Bochner-type results are known for certain classes of…

Mathematical Physics · Physics 2026-03-03 Sohail , Sahil

The purpose of this paper is to study the generalization of inverse semigroups (without order). An ordered semigroup S is called an inverse ordered semigroup if for every a 2 S, any two inverses of a are H-related. We prove that an ordered…

Group Theory · Mathematics 2019-05-13 A. Jamadar , K. Hansda

This is an expository paper which provides a quick introduction to Boolean inverse semigroups and their type monoids, with the emphasis on techniques and insights of the theory, and also treats the connection of the type monoid…

Rings and Algebras · Mathematics 2025-11-06 Ganna Kudryavtseva

An algebra has the Howson property if the intersection of any two finitely generated subalgebras is finitely generated. A simple necessary and sufficient condition is given for the Howson property to hold on an inverse semigroup with…

Group Theory · Mathematics 2016-08-24 Peter R. Jones

In this paper, we describe an algorithm for computing the left, right, or 2-sided congruences of a finitely presented semigroup or monoid with finitely many classes, and an alternative algorithm when the finitely presented semigroup or…

Rings and Algebras · Mathematics 2025-06-26 Marina Anagnostopoulou-Merkouri , Reinis Cirpons , James D. Mitchell , Maria Tsalakou

The idempotent problem of a finitely generated inverse semigroup is the formal language of all words over the generators representing idempotent elements. This note proves that a finitely generated inverse semigroup with regular idempotent…

Group Theory · Mathematics 2013-03-22 Mark Kambites

We continue the study of the structure of general subgroups (in particular maximal subgroups, also known as group $\mathcal{H}$-classes) of special inverse monoids. Recent research of the authors has established that these can be quite…

Group Theory · Mathematics 2025-07-02 Robert D. Gray , Mark Kambites

Recently, sub-indices and sub-factors of groups with connections to number theory, additive combinatorics, and factorization of groups have been introduced and studied. Since all group subsets are considered in the theory and there are many…

Group Theory · Mathematics 2023-10-06 M. H. Hooshmand , M. M. Yousefian Arani

This is the first of a series of papers in which we initiate and develop the theory of reflection monoids, motivated by the theory of reflection groups. The main results identify a number of important inverse semigroups as reflection…

Group Theory · Mathematics 2010-02-01 Brent Everitt , John Fountain