图类αK_(α,α)UβCP(b)中的一类特殊整谱图

A Special Type of the Integral Graphs Which Belong to the Class αK_(α,α)UβCP(b)

图G是一个简单,图G的补图记为G,如果G的谱完全由整数组成,就称G是整谱图,鸡尾酒会图CP (n)=K_(2n)-nK_2(K_(2n)是完全图)和完全二部图K_(a,a)都是整谱图.u_1表示图类αK_(α,α)UβCP(b)的一个主特征值,本文确图了当u_1=2b+1时,图类αK_(α,α)UβCP(b)中的所有的整谱图.

Let G be a simple graph and let ^-G denote its complement. A graph G is called integral if its spectrum consists entirely of integers. Cocktail party graphs CP（n）=K2-nK2 and complete bipartite graphs Kαα, all are integral graphs^[1]. let ^-μ1 denote one of the mian eigenvalues in graphs ^-αKα,αUβCP（b） .In this paper, all integral graphs in ^-αKα,αUβCP（b）,with ^-μ1=2b＋1,are determined.