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arXiv · 1909.03288

Some Bounds on Zeroth-Order General Randi\'c$ Index

Muhammad Kamran Jamil·Ioan Tomescu·Muhammad Imran
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Abstract

For a graph $G$ without isolated vertices, the inverse degree of a graph $G$ is defined as $ID(G)=\sum_{u\in V(G)}d(u)^{-1}$ where $d(u)$ is the number of vertices adjacent to the vertex $u$ in $G$. By replacing $-1$ by any non-zero real number we obtain zeroth-order general Randi\'c index, i.e. $^0R_{\gamma}(G)=\sum_{u\in V(G)}d(u)^{\gamma}$ where $\gamma$ is any non-zero real number. In \cite{xd}, Xu et. al. determined some upper and lower bounds on the inverse degree for a connected graph $G$ in terms of chromatic number, clique number, connectivity, number of cut edges. In this paper, we extend their results and investigate if the same results hold for $\gamma<0$. The corresponding extremal graphs have been also characterized.

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Muhammad Kamran Jamil, Ioan Tomescu, Muhammad Imran. 2019-09-07. Some Bounds on Zeroth-Order General Randi\'c$ Index. https://arxiv.org/abs/1909.03288

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