运筹学学报 ›› 2019, Vol. 23 ›› Issue (1): 72-80.doi: 10.15960/j.cnki.issn.1007-6093.2019.01.008

• 运筹学 • 上一篇    下一篇

新单圈图H(p,tK1,m)的拉普拉斯谱刻画

孙秋实, 杨筱韵, 王力工*, 李希赫, 王朋超   

  1. 西北工业大学理学院应用数学系, 西安 710072
  • 收稿日期:2017-02-09 出版日期:2019-03-15 发布日期:2019-03-15
  • 通讯作者: 王力工 E-mail:lgwangmath@163.com
  • 基金资助:

    国家自然科学基金(No.11871398),陕西省自然科学基础研究计划(No.2018JM1032),国家级大学生创新创业训练计划(No.201610699011)

Laplacian spectral characterizations of new unicyclic graphs H(p,tK1,m)

SUN Qiushi, YANG Xiaoyun, WANG Ligong*, LI Xihe, WANG Pengchao   

  1. Department of Applied Mathematics, School of Science, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2017-02-09 Online:2019-03-15 Published:2019-03-15

摘要:

设图Hp,tK1,m)是一个顶点数为p+mt的连通单圈图,它是由圈Cp的依次相邻的t(1 ≤ tp)个顶点的每一个顶点分别与星K1,m的中心重合而得到的单圈图.现证明单圈图Hp,p K1,5),Hp,(p-1)K1,4)是由它们的拉普拉斯谱确定的,并证明了当p为偶数时,单圈图Hp,2K1,4),Hp,(p-2)K1,4),Hp,(p-3)K1,4)也是由它们的拉普拉斯谱确定的.

关键词: 拉普拉斯矩阵, 拉普拉斯谱确定, 单圈图

Abstract:

Let H(p,tK1,m) denote an unicyclic graph with p+mt vertices obtained from Cp by attaching the center of star K1,m to each one of t mutual adjacent vertices of the cycle Cp, respectively. In this paper, we show that the unicyclic graphs H(p,p K1,5) and H((p,(p-1)K1,4) are determined by their Laplacian spectra, and if p is an even number, then the unicyclic graphs H(p, 2K1,4), H(p,(p-2)K1,4) and H(p,(p-3)K1,4) are also determined by their Laplacian spectra.

Key words: Laplacian matrix, determined by Laplacian spectrum, unicyclic graph

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