Extremal Zeroth-Order General Randic Index Of Thorn Graphs

Shubo Chen1,2, Weijun Liu2, Fengming Yan3
1Department of Mathematics, Hunan City University, Yiyang, Hunan 413000, P. R. China
2College of Mathematics, Central South University, Changsha, Hunan 410075, P. R. China
3Hunan Institue of Humanities Science and Technology, Loudi, Hunan 417000, P. R. China

Abstract

Let \(G = (V, E)\) be a simple connected graph, where \(d_v\) is the degree of vertex \(v\). The zeroth-order Randić index of \(G\) is defined as \(R^0_n(G) = \sum_{v \in V} d_v^\alpha\), where \(\alpha\) is an arbitrary real number. Let \(G^*\) be the thorn graph of \(G\) by attaching \(d_G(v_i)\) new pendent edges to each vertex \(v_i\) (\(1 \leq i \leq n\)) of \(G\). In this paper, we investigate the zeroth-order general Randić index of a class thorn tree and determine the extremal zeroth-order general Randić index of the thorn graphs \(G^*(n,m)\).