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Let $\prod(G)$ be Multiplicative Zagreb index of a graph G. A connected graph is a cactus graph if and only if any two of its cycles have at most one vertex in common, which has been the interest of researchers in the filed of material…

Combinatorics · Mathematics 2016-07-19 Shaohui Wang , Bing Wei

In this paper, we investigate the structural properties of trees and bipartite graphs through the lens of topological indices and combinatorial graph theory. We focus on the First and Second Hyper-Zagreb indices, $HM_1(G)$ and $HM_2(G)$,…

Combinatorics · Mathematics 2025-08-21 Jasem Hamoud

The first Zagreb index $M_{1}(G)$ is equal to the sum of squares of the degrees of the vertices, and the second Zagreb index $M_{2}(G)$ is equal to the sum of the products of the degrees of pairs of adjacent vertices of the underlying…

Combinatorics · Mathematics 2024-04-09 H. M. Nagesh

For a graph $G$, the general reduced second Zagreb index is defined as $$GRM_\lambda (G) = \sum_{uv \in E} (deg(u) + \lambda) (deg(v) + \lambda),$$ where $\lambda$ is an arbitrary real number and $deg (v)$ is the degree of the vertex $v$.…

Combinatorics · Mathematics 2026-04-08 Milan Bašić , Aleksandar Ilić

The first multiplicative Zagreb index of a graph $G$ is the product of the square of every vertex degree, while the second multiplicative Zagreb index is the product of the degree of each edge over all edges. In our work, we explore the…

Combinatorics · Mathematics 2017-04-28 Chunxiang Wang , Jia-Bao Liu , Shaohui Wang

Let $G = (V, E)$ be a graph. The first Zagreb index and the forgotten topological index of a graph $G$ are defined respectively as $\sum_{u \in V} d^2(u)$ and $\sum_{u \in V} d^3(u)$, where $d(u)$ is the degree of vertex $u$ in $G$. If the…

Combinatorics · Mathematics 2024-09-23 Rao Li

The second Zagreb index is $M_2(G)=\sum_{uv\in E(G)}d_{G}(u)d_{G}(v)$. It was found to occur in certain approximate expressions of the total $\pi$-electron energy of alternant hydrocarbons and used by various researchers in their QSPR and…

Combinatorics · Mathematics 2020-06-17 Mingyao Zeng , Hanyuan Deng

For a molecular graph, the first multiplicative Zagreb index $\Pi_1$ is equal to the product of the square of the degree of the vertices, while the second multiplicative Zagreb index $\Pi_2$ is equal to the product of the endvertex degree…

Combinatorics · Mathematics 2017-05-09 Shaohui Wang , Chunxiang Wang , Lin Chen

In this paper, we investigate the degree profile and Gini index of random caterpillar trees (RCTs). We consider RCTs which evolve in two different manners: uniform and nonuniform. The degrees of the vertices on the central path (i.e., the…

Statistics Theory · Mathematics 2019-09-25 Panpan Zhang , Dipak K. Dey

In this paper we compute first and second Zagreb indices of commuting and non-commuting graphs of finite groups and determine several classes of finite groups such that their commuting and non-commuting graphs satisfy Hansen-Vuki\v{c}evi\'c…

Group Theory · Mathematics 2023-04-06 Shrabani Das , Arpita Sarkhel , Rajat Kanti Nath

We determine the degree sequence of the generalized Sierpinski graph and its general first Zagreb index in terms of the same parameters of the base graph G.

Combinatorics · Mathematics 2019-01-23 Ali Behtoei , Fatemeh Attarzadeh , Mahsa Khatibi

Let G be a simple connected molecular graph with vertex set $V(G)$ and edge set $E(G)$. One important modification of classical Zagreb index, called hyper Zagreb index $HM(G)$ is defined as the sum of squares of the degree sum of the…

Discrete Mathematics · Computer Science 2017-03-27 Nilanjan De

The wreath product of graphs is a graph composition inspired by the notion of wreath product of groups, with interesting connections with Geometric Group Theory and Probability. This paper is devoted to the description of some degree and…

Combinatorics · Mathematics 2020-03-20 Matteo Cavaleri , Alfredo Donno

There are various topological indices such as degree based topological indices, distance based topological indices and counting related topological indices etc. These topological indices correlate certain physicochemical properties such as…

Combinatorics · Mathematics 2016-05-09 Shaohui Wang , Jia-Bao Liu , Chunxiang Wang , Sakander Hayat

An extension of the well-known Szeged index was introduced recently, named as weighted Szeged index ($\textrm{sz}(G)$). This paper is devoted to characterizing the extremal trees and graphs of this new topological invariant. In particular,…

Combinatorics · Mathematics 2019-01-16 Jan Bok , Boris Furtula , Nikola Jedličková , Riste Škrekovski

The aim of this paper is to obtain new inequalities for a large family of topological indices restricted to unicyclic graphs and to characterize the set of extremal unicyclic graphs with respect to them. This family includes variable first…

Combinatorics · Mathematics 2021-03-16 Álvaro Martínez-Pérez , José M. Rodríguez

For a (molecular) graph, the first multiplicative Zagreb index $\prod_1(G) $ is the product of the square of every vertex degree, and the second multiplicative Zagreb index $\prod_2(G) $ is the product of the products of degrees of pairs of…

Combinatorics · Mathematics 2017-04-25 Shaohui Wang

This paper establishes sharp bounds for the vulnerability measures of closeness and generalized closeness in graphs and identifies graphs that attain these bounds. It further develops bounds incorporating Zagreb indices for triangle- and…

Combinatorics · Mathematics 2025-06-02 Sanju Vaidya , Cheng Chang

Graph operations are crucial for building complicated network architectures from simple graphs. In [7], authors defined two new variants of Corona product and investigated some topological indices. In this paper, we extended the work and…

Combinatorics · Mathematics 2021-11-23 Rao Tabish , Muhammad Kamran Jamil , Muhammad Waheed

The authors Mili$\breve{c}$evi$\acute{c}$ et al. introduced the reformulated Zagreb indices, which is a generalization of classical Zagreb indices of chemical graph theory. In the paper, we characterize the extremal properties of the first…

Combinatorics · Mathematics 2014-06-30 Shengjin Ji , Xia Li , Yongke Qu