arXiv subjects

Meysam Taheri-Dehkordi

Publications and source records attributed to Meysam Taheri-Dehkordi.

3 recordsLinked to original sources

arXiv2026

The Domination Reciprocal Mean Square Index

We introduce the Domination Reciprocal Mean Square index $DRMS$, a new domination-degree-based topological index obtained by replacing the ordinary degree in the reciprocal mean square index with the domination degree. We establish elementary bounds in terms of graph size and extremal domination degrees, derive a one-parameter family of sharp lower bounds via the power mean, and obtain sharp bounds in terms of several well-known domination-degree-based indices, with a full characterization of the equality cases. We also compute closed-form expressions for $DRMS$ on several standard graph families and for the corona product of two graphs.

math.CO↗

arXiv2026

Sharp Bounds on Diminished Sombor Index

The Diminished Sombor index $(DSO)$ of a simple graph $G$ is a recently introduced degree-based topological index, defined as \[ DSO(G)= \sum_{uv\in E(G)} \frac{\sqrt{d_u^2+d_v^2}} {d_u+d_v} \] In this paper, we establish a collection of new sharp bounds for the $DSO$ index in terms of several fundamental graph parameters and well-known topological indices. In all cases, the proposed bounds rigorously specify the equality conditions, thereby providing a complete characterization of the extremal graphs. These findings deepen the theoretical understanding of the $DSO$ index and provide powerful analytical tools for interdisciplinary applications in mathematical chemistry.

math.GM↗

arXiv2022

Star and Semi-Star Transformations in Fullerene Graphs

A perfect star packing in a graph G is a spanning subgraph of G whose every component is isomorphic to the star graph $K_{1,3}$. A perfect star packing of a fullerene graph G is of type P0 if all the centers of stars lie on hexagons of G. Many fullerene graphs arise from smaller fullerene graphs by applying some transformations. In this paper, we introduce two transformations for fullerene graphs that have perfect star packing of type P0 and examine some characteristics of the graphs obtained from this transformation.

math.CO↗