摘要
对图存在f—因子涉及到独立数和最小度条件进行了研究,得到了下列结果:设a,b为整数且b≥a≥1,b≥2,G是一个有n个顶点的连通图且n≥(a+b)2/a.f(x)是定义在V(G)上的非负整数函数,满足∑x∈V(G)f(x)是偶数且a≤f(x)≤b.如果G满足δ≥(b-1)n+a+b-2a+b-1且δ>(b-2)n+2α-2a+b-2,则G存在f-因子,其中δ和α分别表示图G的最小度和独立数.
A sufficient condition is given depending on the minimum degree and independence number of a graph for the existence of an f factor in a graph,which generalizes a result of T.Niessen on k factors.the following result is also proved:Lte a and b be integers with b ≥ a ≥1, b ≥2, G be a connected graph of order n with n≥(a+b) 2a ,and f an integer-valued functiondefined on V(G) such that a≤f(x)≤b and ∑x∈E(G)f(x)≡0 (mod2).Suppose that G satisfies δ≥(b-1)n+a+b-2a+b-1 and δ>(b-2)n+2a-2a+b-2 ,then G has a factor.
出处
《山东师范大学学报(自然科学版)》
CAS
1997年第1期12-16,共5页
Journal of Shandong Normal University(Natural Science)
关键词
图论
F-因子
独立数
最小度
简单图
graph
factor
f factor
independence number
minimum degree