The smallest sum-connectivity index on trees with \(n\) vertices and \(k\) pendant vertices

Author(s): Yuedan Yao1
1Department of Mathematics, South China Agricultural University, Guangzhou, 510642, P.R. China.
Copyright © Yuedan Yao. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

For a given connected graph \(G\) and a real number \(\alpha\), denote by \(d(u)\) the degree of vertex \(u\) of \(G\), and denote by \(\chi_{\alpha}(G)=\sum_{uv\in E(G)} \big(d(u)+d(v)\big)^{\alpha}\) the general sum-connectivity index of \(G\). In the present note, we determine the smallest general sum-connectivity index of trees (resp., chemical trees) together with corresponding extremal trees among all trees (resp., chemical trees) with \(n\) vertices and \(k\) pendant vertices for \(0<\alpha<1.\)

Keywords: General sum-connectivity index, chemical trees, extremal trees.