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Applied Mathematics A Journal of Chinese Universities  2015, Vol. 30 Issue (3): 333-339    DOI:
    
The star matching number and (signless) Laplacian eigenvalues
HE Chang-xiang1, LIU Shi-qiong2
1. College of Science, University of Shanghai for Science and Technology, Shanghai 200093, China
2. Affiliated Experimental School of Donghua University, Shanghai 201600, China
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Abstract  Let $G$ be a simple graph, and $s\leqslant3$ be an integer. In this paper, if $G$ is a connected graph with order $n$ and $K_{1,s}$-matching number $m(G)$, such that $n>(s+1)m(G)$, then the $m(G)$-th largest Laplacian eigenvalue $\mu_{m(G)}>s+1$. And this result also holds for signless spectrum. As an application, some $Q$-eigenvalue conditions which can determine the Hamiltonicity of a graph are listed.

Key words$K_{1,s}$-matching      circumference      Hamiltonicity     
Received: 21 October 2014      Published: 27 May 2018
CLC:  O157.5  
Cite this article:

HE Chang-xiang, LIU Shi-qiong. The star matching number and (signless) Laplacian eigenvalues. Applied Mathematics A Journal of Chinese Universities, 2015, 30(3): 333-339.

URL:

http://www.zjujournals.com/amjcua/     OR     http://www.zjujournals.com/amjcua/Y2015/V30/I3/333


星匹配数与(无符号)拉普拉斯特征值

设$G$是一个简单无向图, $s\leqslant3$是一个正整数. 文章中, 若$K_{1,s}$-匹配数为 $m(G)$ 的 $n$ 阶连通图 $G$满足 $n>(s+1)m(G)$, 则 $G$的第$m(G)$大 $L$-特征值 $\mu_{m(G)}>s+1$, 然后证明了类似结论对于$Q$-谱也成立. 最后给出了几个判断图的哈密顿性的$Q$-特征值条件.

关键词: $K_{1,s}$-匹配,  周长,  哈密顿性 
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