Original scientific paper

https://doi.org/10.5562/cca2329

On the Narumi-Katayama Index of Composite Graphs

Mohammad Ali Hosseinzadeh ; Department of Mathematics, Faculty of Mathematical Sciences, Tarbiat Modares University, P.O. Box:14115-137, Tehran, Iran
Ali Iranmanesh ; Department of Mathematics, Faculty of Mathematical Sciences, Tarbiat Modares University, P.O. Box:14115-137, Tehran, Iran
Tomislav Došlić ; Faculty of Civil Engineering, University of Zagreb, Kačićeva 26, 10000 Zagreb, Croatia

Abstract

The Narumi-Katayama index of a graph G, denoted by N K(G), is equal to the product of degrees
of vertices of G. In this paper we investigate its behavior under several binary operations on graphs. We
present explicit formulas for its values for composite graphs in terms of its values for operands and some
auxiliary invariants. We demonstrate applications of our results to several chemically relevant classes of
graphs and show how the Narumi-Katayama index can be used as a measure of graph irregularity. (doi:
10.5562/cca2329)

Keywords

Narumi-Katayama index; composite graph; graph product

Hrčak ID:

112790

URI

https://hrcak.srce.hr/112790

Publication date:

16.12.2013.

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