摘要
图 G的一个分数染色是从 G的独立集的集合 ζ到区间 [0 ,1]的一个映射 C,使得对任意顶点x ,都有 :∑S∈ζ,s.t.x∈ sC(S) 1,我们将此分数染色的值定义为 ∑S∈ζc(S) .图 G的分数色数χf(G)是它的所有分数染色的值的下确界 .给出了分数染色临界性的定义并讨论了 Kneser图的分数染色临界性 .
A mapping c from the collection ζ of independent sets of a graph G to the interval is a fractional coloring if for every vertex χ of G we have ∑x∈ζ,s,t,x∈sC(S)=1. The value of a fractional coloring C is ∑x∈ζC(S). The fractional chromatic number {χ\-f(G)} of G is the infimum of the values of fractional colorings of G, The defination of the criticism for fractional chromatic number was given and the criticism for fractional chromatic number of Kneser graph was discussed.
出处
《数学物理学报(A辑)》
CSCD
北大核心
2002年第2期238-243,共6页
Acta Mathematica Scientia
基金
山东省教委科技计划项目 (J0 1P0 1)