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The Journal of Information and Optimization Sciences (JIOS) is a world leading journal publishing high quality, rigorously peer-reviewed original research in all mathematically-oriented theoretical and applied topics in information sciences, optimization sciences and related areas since 1980. Subjects include but are not limited to: • Information Sciences • Optimization Sciences • Control Theory • Operational Research • Decision Sciences • Information Theory • Information Technology • Computer Networks and Communications • Mathematical Programming • Modelling and Simulation • Database Management • Applications to Engineering Sciences • Applications to Technology

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Open Access Research Article

The neighborhood version of the Harmonic index of trees

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pp. 1–19Online FirstJune 2026DOI: 10.47974/JIOS-1910XML
Received:
01 Apr 2024
Published Online:
08 Jun 2026
Article type:
Research Article
Language:
EN
Article no.:
JIOS-1910
Pages:
1–19

Abstract

In a graph G, the neighborhood version of the harmonic index is calculated by summing the values 2/(ΛG (x)+ΛG (y))  for all pairs of adjacent vertices x and y. Here, ΛG (x) represents the total degree of all vertices that are neighbors of vertex x. In this study, we present a lower bound on this kind of index in trees and determine the extremal trees achieve our bound.

Keywords

Subject Classifications

05C3505C07

References

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