New Bounds for Topological Indices on Trees through Generalized Methods Articles uri icon

publication date

  • July 2020

start page

  • 1097

issue

  • 7

volume

  • 12

International Standard Serial Number (ISSN)

  • 2073-8994

abstract

  • Topological indices are useful for predicting the physicochemical behavior of chemical compounds. A main problem in this topic is finding good bounds for the indices, usually when some parameters of the graph are known. The aim of this paper is to use a unified approach in order to obtain several new inequalities for a wide family of topological indices restricted to trees and to characterize the corresponding extremal trees. The main results give upper and lower bounds for a large class of topological indices on trees, fixing or not the maximum degree. This class includes the first variable Zagreb, the Narumi-Katayama, the modified Narumi-Katayama and the Wiener index.

keywords

  • first variable zagreb index; narumi-katayama index; modified narumi-katayama index; wiener index; topological indices; schur-convexity; trees