关于图的变形Randic指数和平均离心距  

On the Variation of the Randic Index and the Average Eccentricity of a Graph

作　　者：孙晓玲[1] 杜建伟[1] SUN Xiao-ling;DU Jian-wei(School of Science,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学理学院,山西太原030051

出　　处：《数学的实践与认识》2021年第14期162-166,共5页Mathematics in Practice and Theory

基　　金：山西省自然科学基金(青年)项目(201901D211227)。

摘　　要：变形Randic指数是著名的Randic指数的一种变形形式.对图G的变形Randic指数R’(G)与平均离心距ε(G)和R′(G)+ε(G)(积R′(G)·ε(G))进行了研究.利用非线性规划和图论的方法,得到了R′(G)+ε(G)(R′(G)·ε(G))的下界,并刻画了相应的极图.The variation of the Randic index is a variant of the well known Randic index.By using the methods of nonlinearly optimization and graph theory,for a graph G,the sum R′(G)+ε(G)(productR′(G)·ε(G))of the variation of the Randic index R’(G)and average eccentricityε(G)was studied.A sharp lower bound of R′(G)+ε(G)(R′(G)·ε(G))was presented,and the corresponding extremal graphs were characterized.

关 键 词：变形Randic指数 离心距 平均离心距 

分 类 号：O157.5[理学—数学]