Results 241 to 250 of about 143,321 (277)

Semigroup algebras of finite ample semigroups

Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2012
An adequate semigroup S is called ample if ea = a(ea)* and ae = (ae)†a for all a ∈ S and e ∈ E(S). Inverse semigroups are exactly those ample semigroups that are regular. After obtaining some characterizations of finite ample semigroups, it is proved that semigroup algebras of finite ample semigroups have generalized triangular matrix representations ...
Xiaojiang Guo, Lin Chen
semanticscholar   +2 more sources

On the measure-theoretic entropy and topological pressure of free semigroup actions

Ergodic Theory and Dynamical Systems, 2016
In this paper we introduce the notions of topological pressure and measure-theoretic entropy for a free semigroup action. Suppose that a free semigroup acts on a compact metric space by continuous self-maps.
Xiaogang Lin, Dongkui Ma, Yupan Wang
semanticscholar   +1 more source

The minimal number of generators of a finite semigroup

Semigroup Forum, 2013
The rank of a finite semigroup is the smallest number of elements required to generate the semigroup. A formula is given for the rank of an arbitrary (not necessarily regular) Rees matrix semigroup over a group.
R. Gray
semanticscholar   +2 more sources

Betti numbers for numerical semigroup rings

, 2016
We survey results related to the magnitude of the Betti numbers of numerical semigroup rings and of their tangent cones.
Dumitru I. Stamate
semanticscholar   +1 more source

Semigroup C * -algebras

, 2016
This is a survey article about recent developments in semigroup C*-algebras. These C*-algebras generated by left regular representations of semigroups have been studied for some time, but it was only recently that several new connections and results were
Xin Li
semanticscholar   +1 more source

Semigroup Actions of Expanding Maps

, 2016
We consider semigroups of Ruelle-expanding maps, parameterized by random walks on the free semigroup, with the aim of examining their complexity and exploring the relation between intrinsic properties of the semigroup action and the thermodynamic ...
M. Carvalho, F. Rodrigues, P. Varandas
semanticscholar   +1 more source

The tight groupoid of an inverse semigroup

Semigroup Forum, 2014
In this work we present algebraic conditions on an inverse semigroup S\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek ...
R. Exel, Enrique Pardo
semanticscholar   +1 more source

Semigroup Varieties and Semigroup Algebras

Semigroup Forum, 1999
The author proves several results of the following flavour: given an important ring-theoretical property \(\Theta\), he describes (both structurally and in the language of identities) all semigroup varieties \(V\) such that for each (or for each finite, or for each locally finite) semigroup \(S\in V\), the semigroup algebra \(FS\) over a field \(F ...
openaire   +2 more sources

The structure of a graph inverse semigroup

, 2014
Given any directed graph E one can construct a graph inverse semigroupG(E), where, roughly speaking, elements correspond to paths in the graph. In this paper we study the semigroup-theoretic structure of G(E).
Z. Mesyan, James D. Mitchell
semanticscholar   +1 more source

EMBEDDING SEMIGROUPS INTO GROUPS, AND THE ASPHERICITY OF SEMIGROUPS

International Journal of Algebra and Computation, 1993
Let \(G = [X,E]\) be a simple graph with vertex set \(X\) and edge set \(E\). For each edge \(e = \{x,y\}\), \(x,y\in X\), suppose we have a non-cancelled semigroup relation \(R_ e: R^{(\ell)}_ e = R^{(r)}_ e\), where \(R^{(\ell)}_ e\), \(R^{(r)}_ e\) are words on \(\{x,y\}\), both involving \(x\), \(y\). Theorem.
Cho, Jung R., Pride, Stephen J.
openaire   +1 more source