Results 91 to 100 of about 4,735 (227)

A note on conservative measures on semigroups

International Journal of Mathematics and Mathematical Sciences, 1992
Consider (S,B,μ) the measure space where S is a topological metric semigroup and μ a countably additive bounded Borel measure. Call μ conservative if all right translations tx:s→sx, x∈S (which are assumed closed mappings) are conservative with respect (S,
N. A. Tserpes
doaj   +1 more source

Littlewood, Paley and almost‐orthogonality: a theory well ahead of its time

Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract The classic paper by Littlewood and Paley [J. Lond. Math. Soc. (1), 6 (1931), 230–233] marked the birth of Littlewood–Paley theory. We discuss this paper and its impact from a historical perspective, include an outline of the results in the paper and their subsequent significance in relation to developments over the last century, and set them ...
Anthony Carbery
wiley   +1 more source

Global weak solutions for the compressible Poisson–Nernst–Planck–Navier–Stokes system

Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract We consider the compressible Poisson–Nernst–Planck–Navier–Stokes (PNPNS) system of equations, governing the transport of charged particles under the influence of the self‐consistent electrostatic potential, in a three‐dimensional bounded domain.
Daniel Marroquin, Dehua Wang
wiley   +1 more source

On generators, relations and D-simplicity of direct products, Byleen extensions, and other semigroup constructions

, 2015
In this thesis we study two different topics, both in the context of semigroup constructions. The first is the investigation of an embedding problem, specifically the problem of whether it is possible to embed any given finitely presentable semigroup ...
Baynes, Samuel
core  

Time-reversal invariance and irreversibility in time-asymmetric quantum mechanics [PDF]

, 2005
The aim of this paper is to analyze the concepts of time-reversal invariance and irreversibility in the so-called 'time-asymmetric quantum mechanics'. We begin with pointing out the difference between these two concepts.
Castagnino, Mario, Gadella, Manuel, Lombardi, Olimpia, Mario Castagnino, Olimpia Lombardi, Manuel Gadella   +5 more
core  

Subsemigroups of virtually free groups : finite Malcev presentations and testing for freeness

, 2006
This paper shows that, given a finite subset X of a finitely generated virtually free group F, the freeness of the subsemigroup of F generated by X can be tested algorithmically. (A group is virtually free if it contains a free subgroup of finite index.)
Robertson, Edmund Frederick, Ruskuc, Nikola, Cain, AJ   +2 more
core   +1 more source

Cayley automaton semigroups

, 2015
Let S be a semigroup, C(S) the automaton constructed from the right Cayley graph of S with respect to all of S as the generating set and ∑(C(S)) the automaton semigroup constructed from C(S). Such semigroups are termed Cayley automaton semigroups. For
McLeman, Alexander Lewis Andrew
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Beyond Regular Semigroups [PDF]

, 2012
The topic of this thesis is the class of weakly U-abundant semigroups. This class is very wide, containing inverse, orthodox, regular, ample, adequate, quasi-adequate, concordant, abundant, restriction, Ehresmann and weakly abundant semigroups.
Wang, Yanhui
core  

Spectral Distribution of Transport Operator Arising in Growing Cell Populations

Journal of Function Spaces, 2014
Transport equation with partly smooth boundary conditions arising in growing cell populations is studied in Lp ...
Hongxing Wu, Shenghua Wang, Dengbin Yuan
doaj   +1 more source

A bivariant theory for the Cuntz semigroup

, 2021
We introduce a bivariant version of the Cuntz semigroup as equivalence classes of order zero maps generalizing the ordinary Cuntz semigroup. The theory has many features formally analogous to KK-theory including a composition product.
Tornetta, Gabriele, Bosa Puigredon, Joan, Zacharias, Joachim   +2 more
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