Results 31 to 40 of about 262,182 (221)

Fourier Algebras on Topological Foundation *-Semigroups. [PDF]

open access: yesSemigroup Forum, 2004
We introduce the notion of the Fourier and Fouier-Stieltjes algebra of a topological *-semigroup and show that these are commutative Banach algebras. For a class of foundation semigroups, we show that these are preduals of von Neumann algebras.
Amini, Massoud, Medghalchi, Alireza
openaire   +2 more sources

A Fibering Theorem for Topological Semigroups [PDF]

open access: yesProceedings of the American Mathematical Society, 1963
The theorem of this paper has appeared under stronger hypotheses and sometimes with weaker conclusions a number of times [1; 2; 3 ], and was known to Koch (in approximately the form of [2]) in 1959 (unpublished). Since it is a useful tool in the study of topological semigroups, and the proof here is simpler, and the theorem stronger than those ...
openaire   +2 more sources

Properties of the subsemigroups of the bicyclic monoid [PDF]

open access: yes, 2002
In this paper we study some properties of the subsemigroups of the bicyclic monoid B, by using a recent description of its subsemigroups. We start by giving necessary and sufficient conditions for a subsemigroup to be finitely generated.
Ruskuc, Nik   +3 more
core   +1 more source

Restricted Algebras on Inverse Semigroups—Part II: Positive Definite Functions

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2011
The relation between representations and positive definite functions is a key concept in harmonic analysis on topological groups. Recently this relation has been studied on topological groupoids.
Massoud Amini, Alireza Medghalchi
doaj   +1 more source

On representation of semigroups of inclusion hyperspaces

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2013
Given a group $X$ we study the algebraic structure of the compact right-topological semigroup $G(X)$ consisting of inclusion hyperspaces on $X$. This semigroup contains the semigroup $\lambda(X)$ of maximal linked systems as a closed subsemigroup.
V. M. Gavrylkiv
doaj   +1 more source

Coupled Dynamics Between Networks and Fields in Physical Space: A Theoretical Perspective

open access: yesAnnalen der Physik, Volume 538, Issue 9, September 2026.
Networks embedded in physical space often communicate through dynamical fields that both mediate and respond to collective behavior. A unified theoretical perspective is presented for these network‐field systems, linking established mathematical frameworks and revealing how feedback between discrete interactions and continuous spatial processes can ...
Alex Arenas   +4 more
wiley   +1 more source

On the growth of generating sets for direct powers of semigroups [PDF]

open access: yes, 2011
For a semigroup S its d-sequence is d(S) = (d1, d2, d3, . . .), where di is the smallest number of elements needed to generate the ith direct power of S.
J. T. Hyde   +12 more
core   +1 more source

Topological monoids of almost monotone injective co-finite partial selfmaps of the set of positive integers

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2013
In this paper we study the semigroup $\mathcal{I}_{\,\infty}^{?\nearrow}(\mathbb{N})$ of partial co-finite almost monotone bijective transformations of the set of positive integers $\mathbb{N}$.
I. Ya. Chuchman, O. V. Gutik
doaj   +1 more source

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

open access: yesBulletin 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   +2 more
wiley   +1 more source

Quasiminimal distal function space and its semigroup compactification

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1995
Quasiminimal distal function on a semitopological semigroup is introduced. The concept of right topological semigroup compactification is employed to study the algebra of quasiminimal distal functions.
R. D. Pandian
doaj   +1 more source

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