Results 1 to 10 of about 142 (106)
Construction of lattice orders on the semigroup ring of a positive rooted monoid
Journal of Algebra, 2003 Let \((M,+,\leq)\) be a strictly partially ordered monoid such that (1) the set of all upper bounds of each element in \(M\) is a chain, (2) each non-zero element \(a\in M\) is positive (i.e ...
Ma, Jingjing, Steinberg, Stuart A.
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On Naturally Ordered Abundant Semigroups with an Adequate Monoid Transversal
Discrete Dynamics in Nature and Society, 2019 In this paper, we study a class of naturally ordered abundant semigroups with an adequate monoid transversal, namely, naturally ordered concordant semigroups with an adequate monoid transversal. After giving some properties of such semigroups, we obtain a structure theorem for naturally ordered concordant semigroups with an adequate monoid transversal.
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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 +3 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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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
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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 +5 more
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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 +3 more
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Is every product system concrete?
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract Is every product system of Hilbert spaces over a semigroup P$P$ concrete, that is, isomorphic to the product system of an E0$E_0$‐semigroup over P$P$? The answer is no if P$P$ is discrete, cancellative and does not embed in a group. However, we show that the answer is yes for a reasonable class of semigroups.
S. Sundar
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Growth problems in diagram categories
Bulletin of the London Mathematical Society, Volume 57, Issue 11, Page 3454-3469, November 2025.Abstract In the semisimple case, we derive (asymptotic) formulas for the growth rate of the number of summands in tensor powers of the generating object in diagram/interpolation categories.
Jonathan Gruber, Daniel Tubbenhauer
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On Endomorphism Universality of Sparse Graph Classes
Journal of Graph Theory, Volume 110, Issue 2, Page 223-244, October 2025.ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
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