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
Let n 〉 r, let lr --- (dl,d2,-,dn) be a non-increasing sequence of nonnegative integers and let Kr+l - e be the graph obtained from Kr+l by deleting one edge. If zr has a realization G containing Kr+l - e as a s...Let n 〉 r, let lr --- (dl,d2,-,dn) be a non-increasing sequence of nonnegative integers and let Kr+l - e be the graph obtained from Kr+l by deleting one edge. If zr has a realization G containing Kr+l - e as a subgraph, then r is said to be potentially Kr+l - e-graphic. In this paper, we give a characterization for a sequence π to be potentially Kr+l - e-graphic.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.
基金Supported by National Natural Science Foundation of China(Nos.11161016 and 10861006)
文摘Let n 〉 r, let lr --- (dl,d2,-,dn) be a non-increasing sequence of nonnegative integers and let Kr+l - e be the graph obtained from Kr+l by deleting one edge. If zr has a realization G containing Kr+l - e as a subgraph, then r is said to be potentially Kr+l - e-graphic. In this paper, we give a characterization for a sequence π to be potentially Kr+l - e-graphic.