摘要
用P(G,λ)表示图G的色多项式.若对任意图H,当P(H,λ)=P(G,λ)时都有H和G同构,则称图G是色唯一的.给出了以下结果:m≥2且k≥0时,完全三部图K(m,m,m+k)是色唯一的;m≥2且m+1>k≥0时,完全三部图K(m,m+1,m+k)是色唯一的.
Let G be a simple graph and P (G, λ) denote the chromatic polynomial of G. A graph C is said to be chromatically unique if for any graph H,P(H,λ) = P(C,λ) implies that H is isomorphic to G. Let K(m,n,r) denote a complete tripartite graph,this paper proved that the complete tripartite graph K(m ,m ,m + k) is chromatically unique if m 〉 2 and k 〉 0,K(m ,m + 1 ,m + k) is chromatically unique if m ≥ 2 and m + 1 〉 k ≥ 0.
出处
《数学的实践与认识》
CSCD
北大核心
2007年第5期129-133,共5页
Mathematics in Practice and Theory
关键词
完全三部图
色唯一图
色划分
色多项式
complete tripartite graph
chromatically unique graph
parti-tion into colour classes
chromatic polynomial