Molecular Trees with Extremal Values of the Second Sombor Index


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Authors: Z. TANG AND H. DENG

DOI: 10.46793/KgJMat2607.1161T

Abstract:

A new geometric background of graph invariants was introduced by Gutman, of which the simplest is the second Sombor index SO2, defined as SO2 = SO2(G) = uvE|d2G(u)−-d2G-(v)|
d2G(u)+d2G (v), where G = (V,E) is a simple graph and dG(v) denotes the degree of v in G. In this paper, the chemical applicability of the second Sombor index is investigated and it is shown that the second Sombor index is useful in predicting physicochemical properties with high accuracy compared to some well-established and often used indices. Also, we obtain a bound for the second Sombor index among all (molecular) trees with fixed numbers of vertices, and characterize those molecular trees achieving the extremal value.



Keywords:

Second Sombor index, tree, molecular tree, extremal value.



References:

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[6]   H. Deng, Z. Tang and R. Wu, Molecular trees with extremal values of Sombor indices, Int. J. Quantum Chem. 121 (2021), Article ID e26622.