Results 1 to 10 of about 54 (54)

On the automorphisms of the power semigroups of a numerical semigroup

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract If H$H$ is a numerical semigroup (i.e., a cofinite subset of the non‐negative integers closed under addition), then the collection of all non‐empty subsets of H$H$ forms a semigroup P(H)$\mathcal {P}(H)$ under the sumset operation induced by addition in H$H$.
Salvatore Tringali, Kerou Wen
wiley   +1 more source

Context‐free graphs and their transition groups

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract Starting from context‐free inverse graphs, we introduce a new class of groups and study their structural properties. We establish closure properties, show that their coword problems are context‐free, analyze torsion elements, and realize them as subgroups of the asynchronous rational group.
Daniele D'Angeli, Francesco Matucci, Davide Perego, Emanuele Rodaro   +3 more
wiley   +1 more source

Geometric inverse semigroup theory: a note on the Milnor–Schwarz lemma for inverse monoids

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract We generalise the Milnor–Schwarz lemma to inverse monoids acting on presheaves of geodesic metric spaces. We provide two proofs of this fact: one only uses elementary techniques, inspired by the arguments for group actions on metric spaces; the other involves a version of the Vietoris–Rips complex, and builds on work of Chung–Martínez–Szakács.
Giorgio Mangioni, Francesco Tesolin
wiley   +1 more source

Maximal subgroups of free projection‐ and idempotent‐generated semigroups with applications to partition monoids

Proceedings of the London Mathematical Society, Volume 133, Issue 2, August 2026.
Abstract This paper investigates the maximal subgroups of a free projection‐generated regular ∗$*$‐semigroup PG(P)${{\textsf {PG}}}(P)$ over a projection algebra P$P$, and their relationship to the maximal subgroups of the free idempotent‐generated semigroup IG(E)${{\textsf {IG}}}(E)$ over the corresponding biordered set E=E(P)$E = {{\textsf {E}}}(P)$.
James East, Robert D. Gray, P. A. Azeef Muhammed, Nik Ruškuc   +3 more
wiley   +1 more source

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, Javad Mashreghi, Prateek Kumar Vishwakarma   +2 more
wiley   +1 more source

Algebraic singular functions are not always dense in the ideal of C∗$C^*$‐singular functions

Bulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract We give the first examples of étale (non‐Hausdorff) groupoids G$\mathcal {G}$ whose C∗$C^*$‐algebras contain singular elements that cannot be approximated by singular elements in Cc(G)$\mathcal {C}_c(\mathcal {G})$. We provide two examples: one is a bundle of groups and the other a minimal and effective groupoid constructed from a self‐similar
Diego Martínez, Nóra Szakács
wiley   +1 more source

Pre A∗‐Algebras and Their Applications in Fuzzy Set Theory

International Journal of Mathematics and Mathematical Sciences, Volume 2026, Issue 1, 2026.
This paper studies Pre A∗‐algebras and their role as an algebraic foundation for fuzzy set theory. By relaxing the key Boolean axioms of distributivity and complementation, Pre A∗‐algebras provide a robust algebraic structure for reasoning with uncertainty.
Gebregziabiher Girum Gebreset, Jonnalagadda Venkateswara Rao, Habtu Alemayehu Atsbaha, Maria A. Lledo   +3 more
wiley   +1 more source

Some Properties of Hyper Ideals in Hyper Hoop‐Algebras

Journal of Applied Mathematics, Volume 2026, Issue 1, 2026.
In this paper, we investigate the structural properties of hyper ideals in hyper hoop‐algebras, a generalization of hoop‐algebras under the framework of hyperstructures. Building upon foundational concepts in hyper group theory and hoop theory, the study introduces definitions for hyper ideals and weak hyper ideals, as well as their absorptive and ...
Teferi Getachew Alemayehu, Wondosen Zemene Norahun, Derso Abeje Engidaw, Gezahagne Mulat Addis, Berhanu Bekele Belayneh, Mohammad Rezwan Habib   +5 more
wiley   +1 more source

Fixed‐Point Hoop Algebras and Lattice‐Theoretic Properties of Derivation Classes

Journal of Mathematics, Volume 2026, Issue 1, 2026.
We introduce three classes of derivations on hoop algebras—pseudo implicative, implicative, and f‐implicative—and investigate their algebraic characteristics through detailed examples. We establish that, under natural conditions, the collection of pseudo implicative derivations forms a bounded distributive lattice.
Ali Madanshekaf, Mohammad Mahdi Motamedi Nezhad, Smritijit Sen   +2 more
wiley   +1 more source

On the Presentation and Cayley Graph of the Bruck–Reilly Idealization Semigroup

Journal of Mathematics, Volume 2026, Issue 1, 2026.
Transferring constructions between different algebraic structures often reveals deep connections and enables the application of techniques from one theory to another. The idealization of the module over a ring, introduced by Nagata in 1962, has been a powerful tool in commutative algebra for decades.
Suha Wazzan, Nurten Urlu Ozalan, A. Sinan Cevik, Smritijit Sen   +3 more
wiley   +1 more source