摘要
设Γ是直径为d且型为(α+1,3)的距离正则图,其中α≥2.用l(c,a,b)表示交叉阵列l(Γ)中列(c,a,b)^t的个数,记r=r(Γ)=l(c1,a1,b1),s=s(Γ)=l(c(r+1),a(r+1),b(r+1)).那末,若c(r+1)=3且a(r+1)=3a,则d=r+s+1,cd=4且Γ为正则拟2d边形.
Let F be a distance-regular graph with order (α + 1,3), where α≥ 2, and let l(c, α, b) denote the number of columns (c, α, b)^t in intersection array l(F). Write r = r(Γ) = l(c1, a1, b1) and s = s(Γ) = l(cr+1, αr+1, br+1). If cr+1 = 3 and αr+l = 3α, then d = r+ s + 1, Cd = 4 and F is a regular near 2d-gon.
出处
《数学进展》
CSCD
北大核心
2007年第5期574-578,共5页
Advances in Mathematics(China)
基金
河北省自然科学基金(No.A20005000141)
关键词
距离正则图
交叉表
团
正则拟多边形
distance-regular graphs
intersection diagram
clique
regular near polygon