(a,b,n)-临界图的几个充分条件

设G是一个图 .设g和f是两个定义在V(G)上的整值函数使得对V(G)所有顶点x有g(x) ≤f(x) .图G被称为 (g ,f,n) 临界图 ,如果删去G的任意n个顶点后的子图都含有G的 (g ,f) 因子 .本文给出了图是 (a ,b ,n) 临界图几个充分条件 ,即度和邻域条件 .进一步指出这些条件是最佳的 .

Sufficient Conditions for Graphs to be (a,b,n)-Critical Graphs

Let G be a graph, and let g and f be two integer-valued functions defined on V(G) such that g(x) ≤ f(x) for all x ∈ V(G). A graph G is called a (g,f,n)- critical graph if after deleting any n vertices of G the remaining graph of G has a (g, f)- factor. In this paper three sufficient conditions are given,which are degree condition and neighborhood condition for graph G to be an (a,b,n)- critical graph. Furthermore,it is shown that results in this paper are sharp.