Results 21 to 30 of about 181 (150)

On the automorphisms of the power semigroups of a numerical semigroup

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract If H$H$ is a numerical semigroup (i.e., a cofinite subset of the non‐negative integers closed under addition), then the collection of all non‐empty subsets of H$H$ forms a semigroup P(H)$\mathcal {P}(H)$ under the sumset operation induced by addition in H$H$.
Salvatore Tringali, Kerou Wen
wiley   +1 more source

Context‐free graphs and their transition groups

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract Starting from context‐free inverse graphs, we introduce a new class of groups and study their structural properties. We establish closure properties, show that their coword problems are context‐free, analyze torsion elements, and realize them as subgroups of the asynchronous rational group.
Daniele D'Angeli, Francesco Matucci, Davide Perego, Emanuele Rodaro   +3 more
wiley   +1 more source

On extensions of completely simple semigroups by groups [PDF]

Semigroup Forum, 2014
An example of an extension of a completely simple semigroup U by a group H is given which cannot be embedded into the wreath product of U by H. On the other hand, every central extension of U by H is shown to be embeddable in the wreath product of U by H, and any extension of U by H is proved to be embeddable in a semidirect product of a completely ...
openaire   +4 more sources

Composition of Fractional Integral and Derivative Operators: Summarised in Tables

Mathematical Methods in the Applied Sciences, Volume 49, Issue 13, Page 14682-14696, 15 September 2026.
ABSTRACT This paper compiles a complete, detailed list of composition properties for Riemann–Liouville fractional differintegrals, in all possible cases for orders anywhere in the complex plane, with the results presented clearly in a table for easy visual consumption.
Arran Fernandez
wiley   +1 more source

Bitranslations of completely simple semigroups and some applications

上海师范大学学报. 自然科学版, 2013
We discuss the bitranslations of completely simple semigroups by the representations given by Petrich M.As an application,we get the structure of an inflation of a completely simple semigroup.Furthermore,we consider the isomorphism between two ...
YANG Yuhui, ZHANG Jiangang
doaj  

Geometry of essential matrix ranges and the Smith–Ward problem for operator systems

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract A d$d$‐tuple of bounded linear selfadjoint operators acting on an infinite‐dimensional separable Hilbert space is said to have the Smith–Ward property if the identity map of the image of the operator system in the Calkin algebra has a completely positive lift.
Douglas Farenick, Chi‐Kwong Li, Sushil Singla   +2 more
wiley   +1 more source

Some properties of completely 0-simple semigroups

上海师范大学学报. 自然科学版, 2013
We consider the properties of completely 0-simple semigroup S when the sandwich matrix P and G are Abelian， and generalize the corresponding results for completely simple semigroups.The elements of S are characterized if the subband of S is a left zero ...
CUI Jufen, ZHANG Jiangang
doaj  

Free semigroups of large critical exponent

Journal of Topology, Volume 19, Issue 3, September 2026.
Abstract For a convergence group equipped with an expanding coarse‐cocycle, we construct finitely generated free subsemigroups, which we call Bishop−−Jonessemigroups$\textit{Bishop--Jones semigroups}$, of critical exponent arbitrarily close to but strictly less than the critical exponent of the ambient group.
Aleksander Skenderi
wiley   +1 more source

Boolean Zero Square (BZS) Semigroups

Sultan Qaboos University Journal for Science
We introduce a new class of semigroups, that we call BZS - Boolean Zero Square-semigroups. A semigroup S with a zero element, 0, is said to be a BZS semigroup if, for every , we have or .
Pinto G.A.
doaj   +1 more source

Higher representation stability for ordered configuration spaces

Journal of Topology, Volume 19, Issue 3, September 2026.
Abstract Using factorization homology with coefficients in twisted commutative algebras (TCAs), we prove two flavors of higher representation stability for the cohomology of (generalized) configuration spaces of a scheme/topological space X$X$. First, we provide an iterative procedure to study higher representation stability using actions coming from ...
Quoc P. Ho
wiley   +1 more source