Results 41 to 50 of about 284 (184)

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

open access: yesJournal 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

The regular radical of semigroup rings of commutative semigroups [PDF]

open access: yesGlasgow Mathematical Journal, 1992
A description of regular group rings is well known (see [12]). Various authors have considered regular semigroup rings (see [17], [8], [10], [11], [4]). These rings have been characterized for many important classes of semigroups, although the general problem turns out to be rather difficult and still has not got a complete solution.
openaire   +2 more sources

Solution of Several Functional Equations on Nonunital Semigroups Using Wilson’s Functional Equations with Involution

open access: yesAbstract and Applied Analysis, 2014
Let S be a nonunital commutative semigroup, σ:S→S an involution, and C the set of complex numbers. In this paper, first we determine the general solutions f,g:S→C of Wilson’s generalizations of d’Alembert’s functional equations  fx+y+fx+σy=2f(x)g(y) and
Jaeyoung Chung, Prasanna K. Sahoo
doaj   +1 more source

Noncommutative polygonal cluster algebras

open access: yesJournal 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   +3 more
wiley   +1 more source

Semigroup compactifications by generalized distal functions and a fixed point theorem

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1991
The notion of “Semigroup compactification” which is in a sense, a generalization of the classical Bohr (almost periodic) compactification of the usual additive reals R, has been studied by J. F. Berglund et. al. [2].
R. D. Pandian
doaj   +1 more source

Some ordered hypersemigroups which enter their properties into their σ-classes [PDF]

open access: yesJournal of Hyperstructures, 2017
An important problem in the theory of ordered hypersemigroups is to describe the ordered hypersemigroups which enter their properties into their σ-classes.
Niovi Kehayopulu
doaj   +1 more source

Equivariant toric geometry and Euler–Maclaurin formulae

open access: yesCommunications on Pure and Applied Mathematics, Volume 79, Issue 3, Page 451-557, March 2026.
Abstract We first investigate torus‐equivariant motivic characteristic classes of toric varieties, and then apply them via the equivariant Riemann–Roch formalism to prove very general Euler–Maclaurin‐type formulae for full‐dimensional simple lattice polytopes.
Sylvain E. Cappell   +3 more
wiley   +1 more source

THE LEFT REGULAR REPRESENTATION OF A COMMUTATIVE SEPARATIVE SEMIGROUP [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 1992
In this paper, a commutative semigroup will be written as a disjoint union of its cancellative subsemigroups. Based on this fact we will define the left regular representation of a commutative separative semigroup and show that this representation is ...
doaj  

Efficient Dynamics: Reduced‐Order Modeling of the Time‐Dependent Schrödinger Equation

open access: yesAdvanced Physics Research, Volume 5, Issue 2, February 2026.
Reduced‐order modeling (ROM) approaches for the time‐dependent Schrödinger equation are investigated, highlighting their ability to simulate quantum dynamics efficiently. Proper Orthogonal Decomposition, Dynamic Mode Decomposition, and Reduced Basis Methods are compared across canonical systems and extended to higher dimensions.
Kolade M. Owolabi
wiley   +1 more source

Control of Open Quantum Systems via Dynamical Invariants

open access: yesAdvanced Quantum Technologies, Volume 9, Issue 2, February 2026.
Dynamical invariants are used to reverse‐engineer control fields for open quantum systems described by time‐dependent Lindblad master equations. By minimizing an analytic leakage functional, the protocol dynamically steers the state along an effectively decoherence‐free path without costly iterative propagation.
Loris M. Cangemi   +4 more
wiley   +1 more source

Home - About - Disclaimer - Privacy