λ_(5-)最优图的一个充分条件

A Sufficient Condition for λ_(5-)Optimal Graphs

设G是一个λ5-连通图,定义ξ5(G)=min{|[X,X]|:X■V(G),|X|=5,G[X]是连通子图},若λ5(G)=ξ5(G),则称G是λ5-最优图.文章给出了满足顶点数v≥17且最小度δ≥v/2-4的λ5-连通图G在一定特殊条件下是λ5-最优图的一个充分条件.

Let G be a λ5-connected graph and let ξ5（G）=min{｜｜：X V（G）,｜X｜=5,G[X] is connected}.The graph G is called a λ5-optimal graph if λ5（G）=ξ5（G）.To give a sufficient condition for λ5-optimal graphs with v≥17 and δ ≥v2-4.