Results 41 to 50 of about 175 (135)

On L-Fuzzy Topological Semigroups

Journal of Mathematical Analysis and Applications, 1993
With \(L\) as a complete Heyting algebra, \(\mu: X\to L\) an \(L\)-fuzzy subset of \(X\), the author has defined \(L\)-fuzzy topological space \((X,\mu,F)\) where \(F\subset L^ x\) satisfies some given conditions; he has defined the category FTOP by the collection of all \(L\)-fuzzy topological spaces with suitably defined morphisms. In a category \(C\)
openaire   +2 more sources

Excursion theory for Markov processes indexed by Lévy trees

Proceedings of the London Mathematical Society, Volume 132, Issue 5, May 2026.
Abstract We develop an excursion theory that describes the evolution of a Markov process indexed by a Lévy tree away from a regular and instantaneous point x$x$ of the state space. The theory builds upon a notion of local time at x$x$ that was recently introduced in the companion paper [Probab. Theory Related Fields. 189 (2024), 1–99].
Armand Riera, Alejandro Rosales‐Ortiz
wiley   +1 more source

Topological and metric entropy for group and semigroup actions

Topological Algebra and its Applications, 2019
It is well-known that the classical definition of topological entropy for group and semigroup actions is frequently zero in some rather interesting situations, e.g. smooth actions of ℤk+ (k >1) on manifolds.
Stoyanov Luchezar
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Complete Invariant ⋆-Metrics on Semigroups and Groups

Axioms, 2022
In this paper, we study the complete ⋆-metric semigroups and groups and the Raǐkov completion of invariant ⋆-metric groups. We obtain the following. (1) Let (X,d⋆) be a complete ⋆-metric space containing a semigroup (group) G that is a dense subset of X.
Shi-Yao He, Jian-Cai Wei, Li-Hong Xie
doaj   +1 more source

The Global Glimm Property for C*‐algebras of topological dimension zero

Bulletin of the London Mathematical Society, Volume 58, Issue 4, April 2026.
Abstract We show that a C∗$C^*$‐algebra with topological dimension zero has the Global Glimm Property (every hereditary subalgebra contains an almost full nilpotent element) if and only if it is nowhere scattered (no hereditary subalgebra admits a finite‐dimensional representation). This solves the Global Glimm Problem in this setting.
Ping Wong Ng, Hannes Thiel, Eduard Vilalta   +2 more
wiley   +1 more source

Noncommutative polygonal cluster algebras

Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract We define a new family of noncommutative generalizations of cluster algebras called polygonal cluster algebras. These algebras generalize the noncommutative surfaces of Berenstein–Retakh, and are inspired by the emerging theory of Θ$\Theta$‐positivity for the groups Spin(p,q)$\mathrm{Spin}(p,q)$.
Zachary Greenberg, Dani Kaufman, Merik Niemeyer, Anna Wienhard   +3 more
wiley   +1 more source

The group of characters of a pseudocompact locally compact semitopological semigroup

Applied General Topology
We prove that each semitopological semigroup has a reflection in the class of abelian cancellative semitopological semigroups. Then we use this reflection to prove that the group of characters of a locally compact pseudocompact topological semigroup with
Julio César Hernández Arzusa
doaj   +1 more source

On topological McAlister semigroups

Journal of Pure and Applied Algebra, 2023
In this paper we consider McAlister semigroups over arbitrary cardinals and investigate their algebraic and topological properties. We show that the group of automorphisms of a McAlister semigroup $\mathcal{M}_λ$ is isomorphic to the direct product $Sym(λ){\times}\mathbb{Z}_2$, where $Sym(λ)$ is the group of permutations of the cardinal $λ$.
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Multiple front and pulse solutions in spatially periodic systems

Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract In this paper, we develop a comprehensive mathematical toolbox for the construction and spectral stability analysis of stationary multiple front and pulse solutions to general semilinear evolution problems on the real line with spatially periodic coefficients.
Lukas Bengel, Björn de Rijk
wiley   +1 more source

On the closure of the extended bicyclic semigroup

Karpatsʹkì Matematičnì Publìkacìï, 2011
In the paper we study the semigroup $mathscr{C}_{mathbb{Z}}$which is a generalization of the bicyclic semigroup. We describemain algebraic properties of the semigroup$mathscr{C}_{mathbb{Z}}$ and prove that every non-trivialcongruence $mathfrak{C}$ on the
I. R. Fihel, O. V. Gutik
doaj