摘要
设G是n阶简单连通图,顶点度序列为d1≥d2≥…≥dn.本文利用矩阵变换的方法给出了图G的拉普拉斯谱半径的新上界,并证明了达到该上界的极图仅有正则二部图或星图.同时还证明了在一定条件下,该上界改进了Li,Liu和Shu等人同类的结论.
Let G be a simple connected graph with n vertices and degree sequence:d_1≥d_2≥...≥d_n.We present a sharp bound for the Laplacian spectral radius by transferring of matrix. We also give the extremal graphs whose Laplacian spectral radius attains the upper bound. Those graphs are eihter regular bipartite graphs or star graphs. Moreover,we prove the result is better than the similar results of Li,Liu and Shu under some conditions.
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第7期155-158,共4页
Journal of Chongqing University
基金
国家自然科学基金资助项目(19971027
10271048)
上海市重点学科建设项目
关键词
拉普拉斯谱半径
最大度
次大度
度序列
laplacian spectral radius
maximum degree
second largest degree
degree sequence
