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Related papers: Note on VDB Topological Indices of k-Cyclic Graphs

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The distance $d(u,v)$ between the vertices $u$ and $v$ of a connected graph $G$ is defined as the number of edges in a minimal path connecting them. The \emph{transmission} of a vertex $v$ of $G$ is defined by $\sigma(v)=\sum\limits_{u\in…

Combinatorics · Mathematics 2018-09-18 Reza Sharafdini , Tamas Reti

We consider topological indices I that are sums of f(deg(u)) f(deg(v)), where {u,v} are adjacent vertices and f is a function. The Randi{\'c} connectivity index or the Zagreb group index are examples for indices of this kind. In earlier…

Combinatorics · Mathematics 2007-05-23 Boris Hollas

For a simple connected graph $G=(V,E)$, let $d(u)$ be the degree of the vertex $u$ of $G$. The general Sombor index of $G$ is defined as $$SO_{\alpha}(G)=\sum_{uv\in E} \left[d(u)^2+d(v)^2\right]^\alpha$$ where $SO(G)=SO_{0.5}(G)$ is the…

Combinatorics · Mathematics 2022-11-08 Peichao Wei , Muhuo Liu

We introduce a degree-based variable topological index inspired on the power (or generalized) mean. We name this new index as the mean Sombor index: $mSO_\alpha(G) = \sum_{uv \in E(G)} \left[\left( d_u^\alpha+d_v^\alpha \right) /2…

Combinatorics · Mathematics 2021-10-07 J. A. Mendez-Bermudez , R. Aguilar-Sanchez , Edil D. Molina , José M. Rodríguez

Let $G=(V,E)$ be a simple graph. The concept of Inverse symmetric division deg index $(ISDD)$ was introduced in the chemical graph theory very recently. In spite of this, a few papers have already appeared with this index in the literature.…

Combinatorics · Mathematics 2024-08-13 Kinkar Chandra Das , B. R. Rakshith , Wojciech Macek

Many existing degree based topological indices can be classified as bond incident degree (BID) indices, whose general form is $BID(G)=\sum_{uv\in E(G)}$ $\Psi(d_{u},d_{v})$, where $uv$ is the edge connecting the vertices $u,v$ of the graph…

Combinatorics · Mathematics 2018-03-14 Akbar Ali , Darko Dimitrov

We perform a detailed statistical study of the distribution of topological and spectral indices on random graphs $G=(V,E)$ in a wide range of connectivity regimes. First, we consider degree-based topological indices (TIs), and focus on two…

Combinatorics · Mathematics 2026-02-23 C. T. Martínez-Martínez , R. Aguilar-Sánchez , J. A. Méndez-Bermúdez

Let $D=(V,A)$ be a digraphs without isolated vertices. A vertex-degree based invariant $I(D)$ related to a real function $\varphi$ of $D$ is defined as a summation over all arcs, $I(D) = \frac{1}{2}\sum_{uv\in A}{\varphi(d_u^+,d_v^-)}$,…

Combinatorics · Mathematics 2021-05-03 Hanyuan Deng , Jiaxiang Yang , Zikai Tang , Jing Yang , Meiling You

Let $d_G(v)$ be the degree of the vertex $v$ in a graph $G$. The Sombor index of $G$ is defined as $SO(G) =\sum_{uv\in E(G)}\sqrt{d^2_G(u)+d^2_G(v)}$, which is a new degree-based topological index introduced by Gutman. Let…

Combinatorics · Mathematics 2021-03-16 Ting Zhou , Zhen Lin , Lianying Miao

For a graph $G$ with vertex set $V_{G}$ and edge set $E_{G}$, the symmetric division deg index is defined as $SDD(G)=\sum\limits_{uv\in E_{G}}(\frac{d_{u}}{d_{v}}+\frac{d_{v}}{d_{u}})$, where $d_{u}$ denotes the degree of vertex $u$ in $G$.…

Combinatorics · Mathematics 2022-07-12 Hechao Liu , Yufei Huang

Recently in 2021, Gutman introduced the Sombor index of a graph, a novel degree-based topological index. It has been shown that the Sombor index efficiently models the thermodynamic properties of chemical compounds. Assume $\mathbb{B}_n^k$…

Combinatorics · Mathematics 2022-08-23 Sakander Hayat , Muhammad Arshad , Kinkar Chandra Das

In this paper, we investigate the Diminished Sombor index (DSO), a recently introduced degree-based topological index for a simple graph $G$, defined as \[ DSO(G) = \sum_{uv \in E} \frac{\sqrt{d_u^2+d_v^2}}{d_u+d_v}, \] where $d_u$ denotes…

Combinatorics · Mathematics 2025-08-12 F. Movahedi

The eccentric connectivity index of a connected graph $G$ is the sum over all vertices $v$ of the product $d_{G}(v) e_{G}(v)$, where $d_{G}(v)$ is the degree of $v$ in $G$ and $e_{G}(v)$ is the maximum distance between $v$ and any other…

Discrete Mathematics · Computer Science 2024-03-11 Gauvain Devillez , Alain Hertz , Hadrien Mélot , Pierre Hauweele

Topological indices are a class of numerical invariants that predict certain physical and chemical properties of molecules. Recently, two novel topological indices, named as Sombor index and reduced Sombor index, were introduced by Gutman,…

Combinatorics · Mathematics 2021-08-24 Hechao Liu , Lihua You , Yufei Huang

Consider a graph $G$ and a real-valued function $f$ defined on the degree set of $G$. The sum of the outputs $f(d_v)$ over all vertices $v\in V(G)$ of $G$ is usually known as the vertex-degree-function indices and is denoted by $H_f(G)$,…

Combinatorics · Mathematics 2023-04-11 Abeer M. Albalahi , Igor Z. Milovanovic , Zahid Raza , Akbar Ali , Amjad E. Hamza

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…

Combinatorics · Mathematics 2025-08-07 Jasem Hamoud , Duaa Abdullah

Let $G=(V,E)$ be a finite simple graph. The Graovac-Ghorbani index of a graph G is defined as $ABC_{GG}(G)=\sum_{uv\in E(G)}\sqrt{\frac{n_u(uv,G)+n_v(uv,G)-2}{n_u(uv,G)n_v(uv,G)}},$ where $n_u(uv,G)$ is the number of vertices closer to…

Combinatorics · Mathematics 2022-02-07 Nima Ghanbari

Let $G$ be a graph with edge set $E(G)$. Denote by $d_w$ the degree of a vertex $w$ of $G$. The sigma index of $G$ is defined as $\sum_{uv\in E(G)}(d_u-d_v)^2$. A connected graph of order $n$ and size $n+k-1$ is known as a connected…

Combinatorics · Mathematics 2022-07-12 Akbar Ali , Abeer M. Albalahi , Abdulaziz M. Alanazi , Akhlaq A. Bhatti , Amjad E. Hamza

Topological indices play a significant role in mathematical chemistry. Given a graph $\mathcal{G}$ with vertex set $\mathcal{V}=\{1,2,\dots,n\}$ and edge set $\mathcal{E}$, let $d_i$ be the degree of node $i$. The degree-based topological…

Combinatorics · Mathematics 2023-10-09 Mingao Yuan

Introduced by Gutman in 2021, the Sombor index is a novel graph-theoretic topological descriptor possessing potential applications in the modeling of thermodynamic properties of compounds. Let G^k_n be the set of all n-vertex connected…

Combinatorics · Mathematics 2022-07-01 Sakander Hayat , Ansar Rehman , Yubin Zhong
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