Results 81 to 90 of about 11,002 (236)
On the automorphisms of the power semigroups of a numerical semigroup
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
Homomorphism–homogeneous graphs [PDF]
AbstractWe answer two open questions posed by Cameron and Nesetril concerning homomorphism–homogeneous graphs. In particular we show, by giving a characterization of these graphs, that extendability to monomorphism or to homomorphism leads to the same class of graphs when defining homomorphism–homogeneity.
Momchil Rusinov, Pascal Schweitzer
openaire +3 more sources
Context‐free graphs and their transition groups
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
wiley +1 more source
Abelian number fields with frobenian conditions
Abstract We study the distribution of abelian number fields with frobenian conditions imposed on the conductor. In particular, we find an asymptotic for the number of abelian field extensions of a number field k$k$ whose conductor is the sum of two squares. We also discuss an application of the Brauer group of stacks to quadratic number fields.
Julie Tavernier
wiley +1 more source
Distributive and Dual Distributive Elements in Hyperlattices
In this paper we introduce and study distributive elements, dual distributive elements in hyperlattices, and prove that these elements forms ∧-semi lattice and ∨-semi hyperlattice, respectively.
Ameri Reza +3 more
doaj +1 more source
Homomorphism indistinguishability
Two graphs G and H are homomorphism indistinguishable over a class of graphs if, for all graphs F ∊ , the number of homomorphisms from F to G is equal to the number of homomorphisms from F to H.
Seppelt, Tim Frederik
core +1 more source
Signed Projective Cubes, a Homomorphism Point of View
ABSTRACT The (signed) projective cubes, as a special class of graphs closely related to the hypercubes, are on the crossroad of geometry, algebra, discrete mathematics and linear algebra. Defined as Cayley graphs on binary groups, they represent basic linear dependencies.
Meirun Chen +2 more
wiley +1 more source
Determinants from homomorphisms
We give a new combinatorial explanation for well-known relations between determinants and traces of matrix powers. Such relations can be used to obtain polynomial-time and poly-logarithmic space algorithms for the determinant. Our new explanation avoids linear-algebraic arguments and instead exploits a classical connection between subgraph and ...
openaire +5 more sources
A Linear Generalization of the Nearly Gorenstein Property, With Applications to Veronese Subalgebras
ABSTRACT We study the nearly Gorenstein property for Veronese subalgebras of (semi‐)standard graded algebras. We introduce a condition (♮)$(\natural)$ for Cohen–Macaulay semi‐standard graded rings, motivated by the study of Ehrhart rings. We show that if a semi‐standard graded algebra R$ R$ satisfies (♮)$(\natural)$, then its Veronese subalgebras R(k)$
Sora Miyashita
wiley +1 more source
Associative triples and homomorphisms between travel groupoids on finite geodetic graphs [PDF]
Sergiy Kozerenko, Yur-Liubomysl Dekhtiar
doaj +1 more source

