TREES WITH MAXIMUM SUM OF THE TWO LARGEST LAPLACIAN EIGENVALUES

被引:0
作者
Zheng, Yirong [1 ]
Li, Jianxi [2 ]
Chang, Sarula [3 ]
机构
[1] Xiamen Univ Technol, Sch Math & Stat, Xiamen, Fujian, Peoples R China
[2] Minnan Normal Univ, Sch Math & Stat, Zhangzhou, Fujian, Peoples R China
[3] Inner Mongolia Agr Univ, Coll Sci, Hohhot, Inner Mongolia, Peoples R China
基金
美国国家科学基金会;
关键词
Tree; Laplacian Eigenvalue; Sum; BROUWERS CONJECTURE; SIGNLESS LAPLACIAN; GRAPH;
D O I
暂无
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Let T be a tree of order n and S-2(T) be the sum of the two largest Laplacian eigenvalues of T. Fritscher et al. proved that for any tree T of order n, S-2(T) <= n + 2 - 2/n. Guan et al. determined the tree with maximum S-2(T) among all trees of order n. In this paper, we characterize the trees with S-2(T) >= n + 1 among all trees of order n except some trees. Moreover, among all trees of order n, we also determine the first [ n-2/2 j trees according to their S-2(T). This extends the result of Guan et al.
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页码:357 / 366
页数:10
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