Results 71 to 80 of about 529,491 (220)

The strong nil-cleanness of semigroup rings

Open Mathematics, 2020
In this paper, we study the strong nil-cleanness of certain classes of semigroup rings. For a completely 0-simple semigroup M=ℳ0(G;I,Λ;P)M={ {\mathcal M} }^{0}(G;I,\text{Λ};P), we show that the contracted semigroup ring R0[M]{R}_{0}{[}M] is ...
Ji Yingdan
doaj   +1 more source

Geometric inverse semigroup theory: a note on the Milnor–Schwarz lemma for inverse monoids

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract We generalise the Milnor–Schwarz lemma to inverse monoids acting on presheaves of geodesic metric spaces. We provide two proofs of this fact: one only uses elementary techniques, inspired by the arguments for group actions on metric spaces; the other involves a version of the Vietoris–Rips complex, and builds on work of Chung–Martínez–Szakács.
Giorgio Mangioni, Francesco Tesolin
wiley   +1 more source

Green index and finiteness conditions for semigroups [PDF]

, 2008
Let S be a semigroup and let T be a subsemigroup of S. Then T acts on S by left and by right multiplication. If the complement S \ T has finitely many strong orbits by both these actions we say that T has finite Green index in S.
R. Gray, Ruskuc, Nik, Gray, Robert Duncan, Gray, R, N. Ruškuc, Ruškuc, N, Ruskuc, Nik; id_orcid   +6 more
core   +1 more source

Module Amenability of Semigroup Algebras under Certain Module Actions

Journal of Mathematical Extension, 2014
In this paper we define a congruence ∼ on inverse semigroup S such that amenability of S is equivalent to amenability of S/ ∼. We study module amenability of semigroup algebra l 1 (S/ ∼) when S is an inverse semigroup with idempotents E and prove ...
A. Sahleh, S. Grailo Tanha
doaj  

Uniqueness problem for accretive Schrödinger operators with complex singular coefficients

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract This paper studies the uniqueness problem for the one‐dimensional Schrödinger operator associated with the formal differential expression l[u]=−u′′+qu+i[(ru)′+ru′]$l[u] =-u^{\prime \prime }+qu + i[(ru)^{\prime }+ru^{\prime }] $ in the complex Hilbert space L2(R)$L^{2}(\mathbb {R})$.
Vladimir Mikhailets, Volodymyr Molyboga
wiley   +1 more source

Idempotent 2x2 matrices over linearly ordered abelian groups [PDF]

Categories and General Algebraic Structures with Applications
In this paper we study multiplicative semigroups of $2\times 2$ matrices over a linearly ordered abelian group with an externally added bottom element. The multiplication of such a semigroup is defined by replacing addition and multiplication by join and
Valdis Laan, Marilyn Kutti
doaj   +1 more source

Cartwright–Sturmfels Hilbert schemes

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract Let S$S$ be the Cox ring of a product of r$r$ projective spaces. In this paper, we study the Cartwright–Sturmfels Hilbert schemes of S$S$, which are multigraded Hilbert schemes that parameterize only radical ideals. Our main result shows that these Hilbert schemes are always smooth and irreducible if the Picard rank r$r$ is at most 2.
Ritvik Ramkumar, Alessio Sammartano
wiley   +1 more source

Some Results on Smarandache Semigroups

Journal of Kufa for Mathematics and Computer, 2013
We discusse in this paper a Smarandache semigroups , a Smarandache  cyclic semigroups and a Smarandache lagrange semigroups.We prove that the Smarandache semigroup with multiplication modulo 2P where p is an odd prime have two subgroups of order P-1and
Sajda Kadhum Mohammed
doaj   +1 more source

Graphs and their associated inverse semigroups

Discrete Mathematics, 2017
17 pages and 1 ...
Tien Chih, Demitri Plessas
openaire   +2 more sources

Equidistribution in 2‐nilpotent Polish groups and triple restricted sumsets

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract The aim of this paper is to establish a Ratner‐type equidistribution theorem for orbits on homogeneous spaces associated with 2$\hskip.001pt 2$‐nilpotent locally compact Polish groups under the action of a countable discrete abelian group.
Ethan Ackelsberg, Asgar Jamneshan
wiley   +1 more source