Results 81 to 90 of about 1,620 (232)
Spreading Speed for a Vector‐Borne Disease System on Non‐Coincident Straight Infinite Cylinders
Studies in Applied Mathematics, Volume 156, Issue 6, June 2026.ABSTRACT Vector‐borne diseases remain an increasing global public health concern. In this work, we investigate the spreading speed of vector‐borne disease via a four‐component reaction–diffusion system posed on non‐coincident straight infinite cylinders, which stands for an unconventional spatial configuration.
Arnaud Ducrot +2 more
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Oppenheim–Schur inequalities for causal products
Bulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.Abstract We establish a class of Oppenheim–Schur‐type inequalities for the convolutional Jury product of positive semidefinite matrices. These results extend the classical Schur and Oppenheim inequalities associated with the Hadamard product to a causal convolutional setting.
Dominique Guillot +2 more
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Neutrosophic Set Approach for Characterizations of Left Almost Semigroups [PDF]
Neutrosophic Sets and Systems, 2016 In this paper we have defined neutrosophic ideals, neutrosophic interior ideals, netrosophic quasi-ideals and neutrosophic bi-ideals (neutrosophic generalized bi-ideals) and proved some results related to them.
Madad Khan +2 more
doaj
On Pseudo-contractibility and Ultra Central Approximate Identity of Some Semigroup Algebras
Journal of Mathematics, 2022 In this paper, we investigate the existence of an ultra central approximate identity for a Banach algebra A and its second dual A∗∗. Also, we prove that for a left cancellative regular semigroup S, ℓ1S∗∗ has an ultra central approximate identity if and ...
Amir Sahami, Seyedeh Fatemeh Shariati
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On regular and intra-regular poe-semigroups
Semigroup Forum, 1984 This note follows a long series of papers of the same author on regular poe-semigroups [see e.g. ibid. 19, 111-121 (1980; Zbl 0434.06015); 23, 85-86 (1981; Zbl 0467.06010); 25, 213-222 (1982; Zbl 0499.06012); 28, 371-372 (1984; Zbl 0534.06006)]. The author establishes a characterization of le-semigroups which are intra-regular and of the intra-regular ...
openaire +3 more sources
The regular radical of semigroup rings of commutative semigroups [PDF]
Glasgow 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.
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Maximum number of zeroes of polynomials on weighted projective spaces over a finite field
Bulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.Abstract We compute the maximum number of rational points at which a homogeneous polynomial can vanish on a weighted projective space over a finite field, provided that the first weight is equal to 1. This solves a conjecture by Aubry, Castryck, Ghorpade, Lachaud, O'Sullivan and Ram, which stated that a Serre‐like bound holds with equality for weighted
Jade Nardi, Rodrigo San‐José
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On Characterization of Relatively Commutative Semigroups
Communications in Advanced Mathematical SciencesThis paper defines a novel semigroup construction, called a relatively commutative semigroup. A semigroup is called relatively commutative if there exist $k,r,t,s\in \mathbb{Z^{+}}$ and $x,y\in S$ such that $(ab)^{k}=b^{r}ax$ and $(ab)^{t}=yba^{s}$ for ...
Rasie Mekera, Didem Yeşil
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Non-commutative finite monoids of a given order n ≥ 4
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014 For a given integer n=p1α1p2α2⋯pkαk$n = p_1^{\alpha _1 } p_2^{\alpha _2 } \cdots p_k^{\alpha _k }$ (k ≥ 2), we give here a class of finitely presented finite monoids of order n. Indeed the monoids Mon(π), where π=〈a1,a2,…,ak|aipiαi=ai, (i=1,2,…,k),aiai+
Ahmadi B., Campbell C.M., Doostie H.
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Isotopy and equivalence of knots in 3‐manifolds
Journal of the London Mathematical Society, Volume 113, Issue 6, June 2026.Abstract Two knots K$K$ and J$J$ in S3$S^3$ are isotopic if and only if they are related by an orientation‐preserving diffeomorphism of S3$S^3$. This claim follows from the fact that any orientation‐preserving self‐diffeomorphism of S3$S^3$ is isotopic to the identity. We show that this same idea applies to any prime oriented closed 3‐manifold.
Paolo Aceto +4 more
wiley +1 more source