Almost Moore and the largest mixed graphs of diameters two and three

Almost Moore mixed graphs appear in the context of the degree/diameter problem as a class of extremal mixed graphs, in the sense that their order is one unit less than the Moore bound for such graphs. The problem of their existence has been considered just for diameter 2. In this paper, we give a co...

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Detalhes bibliográficos
Autores: Dalfó, Cristina, Fiol Mora, Miguel Ángel, López Lorenzo, Ignacio
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10459.1/465749
Acesso em linha:https://doi.org/10.1016/j.laa.2024.01.007
https://hdl.handle.net/10459.1/465749
Access Level:acceso abierto
Palavra-chave:Mixed graph
Degree/diameter problem
Almost Moore graph
Distance matrix
Spectrum
Descrição
Resumo:Almost Moore mixed graphs appear in the context of the degree/diameter problem as a class of extremal mixed graphs, in the sense that their order is one unit less than the Moore bound for such graphs. The problem of their existence has been considered just for diameter 2. In this paper, we give a complete characterization of these extremal mixed graphs for diameters 2 and 3. We also derive some optimal constructions for other diameters.