The split graph Kr∨Ks on r＋s vertices is denoted by Sr,s A graphic sequence π = （d1, d2, …, dn） is said to be potentially Sr,s-graphic if there is a realization of π containing Sr,s as a subgraph. In this paper...The split graph Kr∨Ks on r＋s vertices is denoted by Sr,s A graphic sequence π = （d1, d2, …, dn） is said to be potentially Sr,s-graphic if there is a realization of π containing Sr,s as a subgraph. In this paper, a simple sufficient condition for π to be potentially Sr,s-graphic is obtained, which extends an analogous condition for π to be potentially Kr＋1-graphic due to Yin and Li （Discrete Math. 301 （2005） 218-227）. As an application of this condition, we further determine the values of δ（Sr,s, n） for n _≥3＋ 3s - 1.展开更多
Gould R J等人考虑了下述经典Turan型极值问题的变形:对于给定的图H,确定最小的正偶数σ(H,n),使得对于每一个n项正可图序列π=(d1,d2,…,dn),当σ(π)=d1+d2+…+dn≥σ(H,n)时,π有一个实现G以H作为子图.本文完全确定了σ(K1,1,3,n)之...Gould R J等人考虑了下述经典Turan型极值问题的变形:对于给定的图H,确定最小的正偶数σ(H,n),使得对于每一个n项正可图序列π=(d1,d2,…,dn),当σ(π)=d1+d2+…+dn≥σ(H,n)时,π有一个实现G以H作为子图.本文完全确定了σ(K1,1,3,n)之值,其中Kr,s,t是r×s×t完全三部图.展开更多
基金Supported by the National Natural Science Foundation of China(No.11561017)Natural Science Foundation of Guangxi Province(No.2014GXNSFAA118361)Natural Science Foundation of Hainan Province(No.2016CXTD004)
文摘The split graph Kr∨Ks on r＋s vertices is denoted by Sr,s A graphic sequence π = （d1, d2, …, dn） is said to be potentially Sr,s-graphic if there is a realization of π containing Sr,s as a subgraph. In this paper, a simple sufficient condition for π to be potentially Sr,s-graphic is obtained, which extends an analogous condition for π to be potentially Kr＋1-graphic due to Yin and Li （Discrete Math. 301 （2005） 218-227）. As an application of this condition, we further determine the values of δ（Sr,s, n） for n _≥3＋ 3s - 1.
文摘Gould R J等人考虑了下述经典Turan型极值问题的变形:对于给定的图H,确定最小的正偶数σ(H,n),使得对于每一个n项正可图序列π=(d1,d2,…,dn),当σ(π)=d1+d2+…+dn≥σ(H,n)时,π有一个实现G以H作为子图.本文完全确定了σ(K1,1,3,n)之值,其中Kr,s,t是r×s×t完全三部图.
