Results 11 to 20 of about 2,424 (82)
Dynamic asymptotic dimension and Matui's HK conjecture
Proceedings of the London Mathematical Society, Volume 126, Issue 4, Page 1182-1253, April 2023., 2023 Abstract We prove that the homology groups of a principal ample groupoid vanish in dimensions greater than the dynamic asymptotic dimension of the groupoid (as a side‐effect of our methods, we also give a new model of groupoid homology in terms of the Tor groups of homological algebra, which might be of independent interest).
Christian Bönicke +3 more
wiley +1 more source
Boolean Algebras with Semigroup Operators: Free Product and Free Objects
Journal of Mathematics, Volume 2023, Issue 1, 2023., 2023 Two important algebraic structures are S‐acts and Boolean algebras. Combining these two structures, one gets S‐Boolean algebras, equipped with a compatible right action of a monoid S which is a special case of Boolean algebras with operators. In this article, we considered some category‐theoretic properties of the category Boo‐S of all S‐Boolean ...
H. Barzegar, Carmelo Antonio Finocchiaro
wiley +1 more source
Norms on complex matrices induced by complete homogeneous symmetric polynomials
Bulletin of the London Mathematical Society, Volume 54, Issue 6, Page 2078-2100, December 2022., 2022 Abstract We introduce a remarkable new family of norms on the space of n×n$n \times n$ complex matrices. These norms arise from the combinatorial properties of symmetric functions, and their construction and validation involve probability theory, partition combinatorics, and trace polynomials in non‐commuting variables.
Konrad Aguilar +3 more
wiley +1 more source
Polyhedra, lattice structures, and extensions of semigroups
Journal of the London Mathematical Society, Volume 106, Issue 4, Page 3938-4008, December 2022., 2022 Abstract For an arbitrary rational polyhedron, we consider its decompositions into Minkowski summands and, dual to this, the so‐called free extensions of the associated pair of semigroups. Being free for a pair of semigroups is equivalent to flatness for the corresponding algebras.
Klaus Altmann +2 more
wiley +1 more source
Hypersurface singularities with monomial Jacobian ideal
Bulletin of the London Mathematical Society, Volume 54, Issue 3, Page 1067-1081, June 2022., 2022 Abstract We show that every convergent power series with monomial extended Jacobian ideal is right equivalent to a Thom–Sebastiani polynomial. This solves a problem posed by Hauser and Schicho. On the combinatorial side, we introduce a notion of Jacobian semigroup ideal involving a transversal matroid.
Raul Epure, Mathias Schulze
wiley +1 more source
Automaton semigroup constructions [PDF]
, 2013 The aim of this paper is to investigate whether the class of automaton semigroups is closed under certain semigroup constructions. We prove that the free product of two automaton semigroups that contain left identities is again an automaton semigroup. We
Brough, Tara, Cain, Alan J.
core +1 more source
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
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
wiley +1 more source
Commutative positive varieties of languages
, 2017 We study the commutative positive varieties of languages closed under various operations: shuffle, renaming and product over one-letter ...
Almeida, Jorge +2 more
core +1 more source
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
wiley +1 more source