Remarks on harmonic index of graphs

被引：0
|
作者：
Liu, Jingzhong [2 ]
Zhang, Qianhong [1 ,3 ]
机构：
[1] Guizhou Coll Finance & Econ, Guizhou Key Lab Econ Syst Simulat, Guiyang 550004, Guizhou, Peoples R China
[2] Hunan Inst Technol, Dept Comp & Informat Sci, Hengyang 421002, Hunan, Peoples R China
[3] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China
来源：
UTILITAS MATHEMATICA | 2012年 / 88卷
关键词：
Degree; harmonic index; Bounds; Topological index; CONNECTIVITY;
D O I：
暂无
中图分类号：
O29 [应用数学];
学科分类号：
070104 ;
摘要：
The harmonic index of a connected graph G, denoted by H(G), is defined as H(G) = Sigma(u upsilon is an element of E(G)) 2/d(u)+2 upsilon, where cit, is the degree of a vertex v in G. In this note, we extend a result of Zhong concerning the upper bound for harmonic index of unicyclic graphs to general connected graphs. In addition, we give a direct proof of Zhong's another result on the lower bound for harmonic index of trees.
引用
收藏
页码：281 / 285
页数：5
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