Sharp inequalities for the atom-bond sum-connectivity index of graph operations

Year 2026, Issue: Advanced Online Publication, 1 - 11

Zaryab Hussain

https://doi.org/10.15672/hujms.1456544

Abstract

The atom-bond sum-connectivity index of a graph $G$ is defined as
\begin{equation*}
ABSC(G)=\sum\limits_{uv\in E(G)}\sqrt{\frac{d(u)+d(v)-2}{d(u)+d(v)}}=\sum\limits_{uv\in E(G)}\sqrt{1-\frac{2}{d(u)+d(v)}}
\end{equation*}
where $d(u)$ and $d(v)$ represent the degrees of vertices $u$ and $v$ respectively. In this paper, we will determine the sharp upper and lower bounds for the atom-bond sum-connectivity index of a series of graph operations, including the addition $\left(G+H\right)$, the Cartesian product$\left(G\times H\right)$, the composition $\left(G[H]\right)$, and the corona product $\left(GoH\right)$ of graphs, where $G$ and $H$ representing graphs. We also identify and describe the graphs that achieve extremal values.

Keywords

ABSC index , graph operations , sharp inequalities , extremal bounds

Ethical Statement

This work is done by me. No AI used for this manuscript.

References

• [1] A. Ali, B. Furtula, I. Redžepović and I. Gutman, Atom-bond sum-connectivity index, J. Math. Chem. 60, 2081-2093, 2022.