摘要
图G是一个简单图,图G的补图记为■.如果G的谱完全由整数组成,我们就说G是整图.如果■是整图,我们将讨论它是具有如下形式的一种整图■其中各参数满足的条件见文中定理.
Let G be a simple graph and let ↑-G denotes its complement. We say that G is integral graph if its spectrum consists entirely of integers. If ↑--αKα∪βKb is integral we show that it belongs to the class of integral graphs:↑--[kt/τx0+mt/τz]K(l+ln)k+ln∪[kt/τy0+(t+ln)k+lm/τz]nKlm wher(1)t,k ,l,m,n∈such that(m,n)+1,)n,t)=1,(l,t)=1;(2)τ=((t+ln)k+lm,mt)such that τ|kt;(3)(x0,y0)ys a particular solution of the linear Diophantine equation((t+ln)k+lm)x-(mt)y=τ(4)z≥z0 where z0 is the least integar such that(kt/τx0+mt/τz0)≥1 and(kt/τy0+(t+ln)k+lm/τz0)≥1.
出处
《青海师范大学学报(自然科学版)》
2007年第1期13-16,共4页
Journal of Qinghai Normal University(Natural Science Edition)
关键词
整图
主特征值
阶
丢番图方程
integral graph
main eigenvalue
order
Diophantine equation