Mathematics (Nov 2019)

<i>f</i>-Polynomial on Some Graph Operations

  • Walter Carballosa,
  • José Manuel Rodríguez,
  • José María Sigarreta,
  • Nodari Vakhania

DOI
https://doi.org/10.3390/math7111074
Journal volume & issue
Vol. 7, no. 11
p. 1074

Abstract

Read online

Given any function f : Z + → R + , let us define the f-index I f ( G ) = ∑ u ∈ V ( G ) f ( d u ) and the f-polynomial P f ( G , x ) = ∑ u ∈ V ( G ) x 1 / f ( d u ) − 1 , for x > 0 . In addition, we define P f ( G , 0 ) = lim x → 0 + P f ( G , x ) . We use the f-polynomial of a large family of topological indices in order to study mathematical relations of the inverse degree, the generalized first Zagreb, and the sum lordeg indices, among others. In this paper, using this f-polynomial, we obtain several properties of these indices of some classical graph operations that include corona product and join, line, and Mycielskian, among others.

Keywords