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相关论文: Bounds on Trees with Topological Indices Among Deg…

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In this paper, we have studied bounds based on topological indicators, from which we selected Albertson index $\mathrm{irr}$ and the Sigma index $\sigma$. The Sigma index was defined through the following relationship: \[…

组合数学 · 数学 2025-06-16 Jasem Hamoud , Alexei Belov-Kanel , Duaa Abdullah

In this paper, we presented a study of topological indices on trees, where we show a relationship with irregularity of Albertson index and minimum, maximum degrees $\delta,\Delta$ of graph $G$, where contribute vital roles in determining…

组合数学 · 数学 2025-11-26 Jasem Hamoud , Artem Kornosov

In this paper, we refer to a asymptotic degree sequence as $\mathscr{D}=(d_1,d_2,\dots,d_n)$. The examination of topological indices on trees gives us a general overview through bounds to find the maximum and minimum bounds which reflect…

组合数学 · 数学 2025-12-16 Jasem Hamoud , Duaa Abdullah

In this paper, we presents novel and sharp bounds on the Albertson index of trees, revealing deep connections between degree sequences and graph irregularity where the Albertson index of Caterpillar tree satisfy \[…

综合数学 · 数学 2025-12-16 Jasem Hamoud , Duaa Abdullah

In this paper, we provide the irregularity properties of trees with strong support vertex by analyzing two prominent topological indices: the Albertson index and the Sigma index. We further establish extremal bounds for both indices across…

组合数学 · 数学 2025-05-13 Jasem Hamoud , Duaa Abdullah

In this paper, degree-based topological indices play a key role in the structural analysis of graphs in this paper and have significant uses in chemical graph theory. We investigate the connections between three such tree indices: the…

组合数学 · 数学 2026-03-10 Duaa Abdullah , Jasem Hamoud

This study explores the irregularity properties of trees with prescribed degree sequences by analyzing two prominent topological indices: the Albertson index and the sigma index. With a particular emphasis on caterpillar trees -frequently…

组合数学 · 数学 2025-12-16 Jasem Hamoud , Alexey Belov Yakovlevich , Muaadh Almahalebi , Duaa Abdullah

In this paper we give new bounds for a several vertex-based and edge-based topological indices of graphs: Albertson irregularity index, degree variance index, Mostar and the first Zagreb index. Moreover, we give a new upper bound for the…

组合数学 · 数学 2022-10-25 Arber Avdullahu , Slobodan Filipovski

We establish sharp extremal bounds on the Albertson and Sigma irregularity indices for trees with prescribed degree sequences, with emphasis on caterpillar trees as key extremal configurations. New lower and upper bounds are derived in…

组合数学 · 数学 2026-03-12 Jasem Hamoud , Duaa Abdullah

Let $\mathbb{G} = (\mathcal{V}, \mathcal{E})$ be a simple connected graph, where $\mathcal{V}$ and $\mathcal{E}$ denote the vertex and edge sets, respectively. The first Zagreb index is defined as $\mathcal{M}_{1}(\mathbb{G}) = \sum_{v \in…

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 products of degrees of pairs of adjacent vertices. In this paper,…

组合数学 · 数学 2017-04-21 Shaohui Wang , Chunxiang Wang , Lin Chen , Jia-Bao Liu

In this paper, the study of extreme value bounds for topological indices is crucial for understanding their influence on trees and bipartite graphs. For integers $\alpha, p$ satisfying $1 \leq p \leq \alpha \leq \Delta - 3$, the minimum…

组合数学 · 数学 2025-12-16 Jasem Hamoud , Duaa Abdullah

We derive sharp lower bounds for the first and the second Zagreb indices ($M_1$ and $M_2$ respectively) for trees and chemical trees with the given number of pendent vertices and find optimal trees. $M_1$ is minimized by a tree with all…

组合数学 · 数学 2015-07-20 Mikhail Goubko , Tamás Réti

Let $G=(V,E)$ be a simple graph with $n = |V|$ vertices and $m = |E|$ edges. The first and second Zagreb indices are among the oldest and the most famous topological indices, defined as $M_1 = \sum_{i \in V} d_i^2$ and $M_2 = \sum_{(i, j)…

组合数学 · 数学 2011-04-22 Aleksandar Ilić , Dragan Stevanović

A topological index reflects the physical, chemical and structural properties of a molecule, and its study has an important role in molecular topology, chemical graph theory and mathematical chemistry. It is a natural problem to…

组合数学 · 数学 2022-07-08 Rui Song , Qiongxiang Huang

The first multiplicative Zagreb index $\Pi_1$ of a graph $G$ is the product of the square of every vertex degree, while the second multiplicative Zagreb index $\Pi_2$ is the product of the products of degrees of pairs of adjacent vertices.…

组合数学 · 数学 2019-07-01 Fazal Hayat

The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the first variable Zagreb index $M_1^\alpha$, and to characterize the set of extremal graphs with respect to them. Our main…

组合数学 · 数学 2018-06-07 Alvaro Martínez-Pérez , José M. Rodríguez

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…

组合数学 · 数学 2020-06-17 Mingyao Zeng , Hanyuan Deng

The first Zagreb index of a graph $G$ is the sum of squares of the vertex degrees in a graph and the second Zagreb index of $G$ is the sum of products of degrees of adjacent vertices in $G$. The imbalance of an edge in $G$ is the numerical…

综合数学 · 数学 2020-02-25 Sudev Naduvath , Johan Kok

In this paper, the investigates Adriatic indices, specifically the sum lordeg index where it defined as $SL(G) = \sum_{u \in V(G)} \deg_G(u) \sqrt{\ln \deg_G(u)}$ and the variable sum exdeg index $SEI_a(G)$ for $a>0$, $a\neq 1$. We present…

组合数学 · 数学 2025-08-07 Jasem Hamoud , Duaa Abdullah
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