Results 51 to 60 of about 112,333 (192)
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
wiley +1 more source
Unification in Commutative Semigroups
Journal of Algebra, 1998 Let \(V\) be a variety of algebras and \(X\) a fixed set of variables. Every function \(\sigma\) assigning \(V\)-terms to variables is called a substitution. If \(p\) is a term and \(\sigma\) is a substitution, the term \(\sigma(p)\) is defined in the usual way. Let \(\Sigma\) be a finite set of equations over \(V\).
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Commuting Pairs in Quasigroups
Journal of Combinatorial Designs, Volume 33, Issue 11, Page 418-427, November 2025.ABSTRACT A quasigroup is a pair ( Q , ∗ ), where Q is a nonempty set and ∗ is a binary operation on Q such that for every ( a , b ) ∈ Q 2, there exists a unique ( x , y ) ∈ Q 2 such that a ∗ x = b = y ∗ a. Let ( Q , ∗ ) be a quasigroup. A pair ( x , y ) ∈ Q 2 is a commuting pair of ( Q , ∗ ) if x ∗ y = y ∗ x.
Jack Allsop, Ian M. Wanless
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Труды Института системного программирования РАН, 2018 In this paper we study the equivalence problem in the model of sequential programs which assumes that some instructions are commutative and absorbing. Two instructions are commutative if the result of their executions does not depend on an order of their
V. V. Podymov, V. A. Zakharov
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LC-commutative permutable semigroups
Semigroup Forum, 1996 A semigroup \(S\) is called permutable if \(\rho \circ \sigma = \sigma \circ \rho\) for all congruences \(\rho\), \(\sigma\) on \(S\). A semigroup is called \(L\)-commutative if for every \(a, b \in S\) there is an element \(x \in S^1\) such that \(ab = xba\).
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Finite models for positive combinatorial and exponential algebra
Bulletin of the London Mathematical Society, Volume 57, Issue 11, Page 3380-3400, November 2025.Abstract We use high girth, high chromatic number hypergraphs to show that there are finite models of the equational theory of the semiring of non‐negative integers whose equational theory has no finite axiomatisation, and show this also holds if factorial, fixed base exponentiation and operations for binomial coefficients are adjoined.
Tumadhir Alsulami, Marcel Jackson
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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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Ratio Mathematica, 1997 In this paper, the very thin commutative idem-potent semigroups are characterized. As application, the structure of all very thin hyperlattices is determined.
Cornelia Gutan
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Efficient Simulation of Open Quantum Systems on NISQ Trapped‐Ion Hardware
Advanced Quantum Technologies, Volume 8, Issue 9, September 2025.Open quantum systems exhibit rich dynamics that can be simulated efficiently on quantum computers, allowing us to learn more about their behavior. This work applies a new method to simulate certain open quantum systems on noisy trapped‐ion quantum hardware.
Colin Burdine +3 more
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Commutative cancellative semigroups without idempotents [PDF]
Pacific Journal of Mathematics, 1975 In dieser Arbeit werden kürzbare abelsche Halbgruppen ohne Idempotente (sogenannte CCIF-Halbgruppen) untersucht. Da jede CCIF-Halbgruppe ein Halbverband von \(\mathfrak{R}\)-Halbgruppen ist, kann man hoffen, dass sich Methoden und Ergebnisse aus der Theorie der \(\mathfrak{R}\)-Halbgruppen auf CCIF-Halbgruppen übertragen lassen. Dieser Überlegung folgt
Hamilton, H. B. +2 more
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