On the number of L-shapes in embedding dimension four numerical semigroups

Minimum distance diagrams, also known as L-shapes, have been used to study some properties related to weighted Cayley digraphs of degree two and embedding dimension three numerical semigroups. In this particular case, it has been shown that these discrete structures have at most two related L-shapes...

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Detalles Bibliográficos
Autores: Aguiló Gost, Francisco de Asis L.|||0000-0003-1572-8486, García Sánchez, Pedro A., Llena, David
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/80110
Acceso en línea:https://hdl.handle.net/2117/80110
https://dx.doi.org/10.1016/j.disc.2015.05.019
Access Level:acceso abierto
Palabra clave:Graph theory
Combinatorial analysis
Numerical semigroup
Factorization
Weighted Cayley digraph
L-shape
LOOP NETWORKS
Grafs, Teoria de
Combinatòria
Classificació AMS::05 Combinatorics::05C Graph theory
Classificació AMS::11 Number theory::11D Diophantine equations
Àrees temàtiques de la UPC::Matemàtiques i estadística::Matemàtica discreta::Combinatòria
Àrees temàtiques de la UPC::Matemàtiques i estadística::Matemàtica discreta::Teoria de grafs
Descripción
Sumario:Minimum distance diagrams, also known as L-shapes, have been used to study some properties related to weighted Cayley digraphs of degree two and embedding dimension three numerical semigroups. In this particular case, it has been shown that these discrete structures have at most two related L-shapes. These diagrams are proved to be a good tool for studying factorizations and the catenary degree for semigroups and diameter and distance between vertices for digraphs.; This maximum number of L-shapes has not been proved to be kept when increasing the degree of digraphs or the embedding dimension of semigroups. In this work we give a family of embedding dimension four numerical semigroups S-n, for odd n >= 5, such that the number of related L-shapes is n+3/2. This family has her analogue to weighted Cayley digraphs of degree three.; Therefore, the number of L-shapes related to numerical semigroups can be as large as wanted when the embedding dimension is at least four. The same is true for weighted Cayley digraphs of degree at least three. This fact has several implications on the combinatorics of factorizations for numerical semigroups and minimum paths between vertices for weighted digraphs. (C) 2015 Elsevier B.V. All rights reserved.