On the b-coloring of P4-tidy graphs

A b-coloring of a graph is a coloring such that every color class admits a vertex adjacent to at least one vertex receiving each of the colors not assigned to it. The b-chromatic number of a graph G, denoted by χb(G), is the maximum number t such that G admits a b-coloring with t colors. A graph G i...

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Detalhes bibliográficos
Autores: Velasquez, C.I.B., Bonomo, F., Koch, I.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2011
País:Argentina
Recursos:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
Repositório:Biblioteca Digital (UBA-FCEN)
Idioma:inglês
OAI Identifier:paperaa:paper_0166218X_v159_n1_p60_Velasquez
Acesso em linha:http://hdl.handle.net/20.500.12110/paper_0166218X_v159_n1_p60_Velasquez
Access Level:Acceso aberto
Palavra-chave:b-coloring
b-continuity
b-monotonicity
P4-tidy graphs
B-chromatic number
Chromatic number
Graph G
Induced subgraphs
Monotonicity
Polynomial-time algorithms
Color
Coloring
Graphic methods
Polynomial approximation
Graph theory
Descrição
Resumo:A b-coloring of a graph is a coloring such that every color class admits a vertex adjacent to at least one vertex receiving each of the colors not assigned to it. The b-chromatic number of a graph G, denoted by χb(G), is the maximum number t such that G admits a b-coloring with t colors. A graph G is b-continuous if it admits a b-coloring with t colors, for every t=χ(G),...,χb(G), and it is b-monotonic if χb(H1)<χb(H2) for every induced subgraph H1 of G, and every induced subgraph H2 of H1. In this work, we prove that P4-tidy graphs (a generalization of many classes of graphs with few induced P4s) are b-continuous and b-monotonic. Furthermore, we describe a polynomial time algorithm to compute theb-chromatic number for this class of graphs. © 2010 Elsevier B.V. All rights reserved.