English
Related papers

Related papers: The Second Zagreb Indices of Graphs with Given Deg…

200 papers

{\small The Wiener index $W(G)$ of a graph $G$ is the sum of the distances between all pairs of vertices in the graph. The Szeged index $Sz(G)$ of a graph $G$ is defined as $Sz(G)=\sum_{e=uv \in E}n_u(e)n_v(e)$ where $n_u(e)$ and $n_v(e)$…

Combinatorics · Mathematics 2012-10-25 Lily Chen , Xueliang Li , Mengmeng Liu

For a simple graph, we introduce a notion of the star sequence and prove that the star sequence and the frequently sequences of a graph are inverses of each other from a combinatorial point of view. As a consequence, we express the general…

Combinatorics · Mathematics 2018-09-19 Leonid Bedratyuk , Oleg Savenko

In a connected graph G, the distance between two vertices of G is the length of a shortest path between these vertices. The eccentricity of a vertex u in G is the largest distance between u and any other vertex of G. The total-eccentricity…

Combinatorics · Mathematics 2017-11-21 Rashid Farooq , Mehar Ali Malik , Juan Rada

This paper surveys some recent results and progress on the extremal prob- lems in a given set consisting of all simple connected graphs with the same graphic degree sequence. In particular, we study and characterize the extremal graphs…

Combinatorics · Mathematics 2015-10-08 Xiao-Dong Zhang

In a graph, we assign distinct integers to the vertices, and take the sum of two integers if they are on two adjacent vertices. The minimum possible number of different sums is the \emph{sum index} of this graph. In this paper, we present…

Combinatorics · Mathematics 2025-07-29 Dheer Noal Desai , Runze Wang

The reciprocal degree resistance distance index of a connected graph $G$ is defined as $RDR(G)=\sum\limits_{\{u,v\}\subseteq V(G)}\frac {d_G(u)+d_G(v)}{r_G(u,v)}$, where $r_G(u,v)$ is the resistance distance between vertices $u$ and $v$ in…

Combinatorics · Mathematics 2018-10-09 Gui-Dong Yu , Xing-Xing Li , Gai-Xiang Cai

In this work, we compute the first and second Zagreb indices for the commuting conjugacy class graphs associated with finite groups. We identify multiple classes of finite groups whose commuting conjugacy class graphs are shown to satisfy…

Group Theory · Mathematics 2025-06-03 Shrabani Das , Rajat Kanti Nath , Yilun Shang

In the original article ``Wiener index of Eulerian graphs'' [Discrete Applied Mathematics Volume 162, 10 January 2014, Pages 247-250], the authors state that the Wiener index (total distance) of an Eulerian graph is maximized by the cycle.…

Combinatorics · Mathematics 2023-09-12 Stijn Cambie

Over all graphs (or unicyclic graphs) of a given order, we characterise those graphs that minimise or maximise the number of connected induced subgraphs. For each of these classes, we find that the graphs that minimise the number of…

Combinatorics · Mathematics 2019-09-18 Audace A. V. Dossou-Olory

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 $\mathbb{G} = (\mathcal{V}, \mathcal{E})$ 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…

General Mathematics · Mathematics 2025-08-08 Waqar Ali , Mohamad Nazri Bin Husin , Muhammad Faisal Nadeem , Muqaddas Jabin

The variation of the Randi\'c index $ R'(G) $ of a graph $G$ is defined by\ $R(G) = \sum_{uv \in E(G)}\frac 1{\max \{d(u) d(v)\}}$, where $d(u)$ is the degree of vertex $u$ and the summation extends over all edges $uv$ of $G$. Let $G(k,n)$…

Combinatorics · Mathematics 2016-02-12 Milica Milivojevic , Ljiljana Pavlovic

Let $\G(v,e)$ be the set of all simple graphs with $v$ vertices and $e$ edges and let $P_2(G)=\sum d_i^2$ denote the sum of the squares of the degrees, $d_1, >..., d_v$, of the vertices of $G$. It is known that the maximum value of $P_2(G)$…

Let $G$ be a connected graph. The edge revised Szeged index of $G$ is defined as $Sz^{\ast}_{e}(G)=\sum\limits_{e=uv\in E(G)}(m_{u}(e|G)+\frac{m_{0}(e|G)}{2})(m_{v}(e|G)+\frac{m_{0}(e|G)}{2})$, where $m_{u}(e|G)$ (resp., $m_{v}(e|G)$) is…

Combinatorics · Mathematics 2018-04-18 Shengjie He , Rong-Xia Hao , Deming Li

The weighted adjacency matrix $A_{f}(G)$ of a simple graph $G=(V,E)$ is the $|V|\times|V|$ matrix whose $ij$-entry equals $f(d_{i},d_j)$, where $f(x,y)$ is a symmetric function such that $f(d_i,d_j)>0$ if $ij\in E$ and $f(d_i,d_j)=0$ if…

Combinatorics · Mathematics 2023-03-23 Jiachang Ye , Junli Hu , Xiaodan Chen

Suppose $G$ is a simple graph with edge set $E(G)$. The Randi\'{c} index $R(G)$ is defined as $R(G)=\sum_{uv\in E(G)}\frac{1}{\sqrt{deg_{G}(u)deg_{G}(v)}}$, where $deg_G(u)$ denotes the vertex degree of $u$ in $G$. In this paper, the first…

Combinatorics · Mathematics 2019-07-26 Ali Reza Ashrafi , Ali Ghalavand , Marzieh Pourbabaee

The forgotten topological index of a graph $G$, denoted by $F(G)$, is defined as the sum of weights $d(u)^{2}+d(v)^{2}$ over all edges $uv$ of $G$ , where $d(u)$ denotes the degree of a vertex $u$. In this paper, we give sharp upper bounds…

Combinatorics · Mathematics 2021-02-05 A. Jahanbani , L. Shahbazi , S. M. Sheikholeslami , R. Rasi , J. Rodriguez

Let $R$ be a commutative ring with unity. The essential ideal graph $\mathcal{E}_{R}$ of $R$ is a graph whose vertex set consists of all nonzero proper ideals of \textit{R}. Two vertices $\hat{I}$ and $\hat{J}$ are adjacent if and only if…

Combinatorics · Mathematics 2024-07-04 Jamsheena P , Chithra A

In this manuscript, we delve into the exploration of the first and second Zagreb connection indices of both polyomino chains and random polyomino chains. Our methodology relies on the utilization of Markov chain theory. Within this…

Disordered Systems and Neural Networks · Physics 2024-05-22 Sayle Sigarreta , Hugo Cruz-Suarez

The Szeged index of a graph is an invariant with several applications in chemistry. The power graph of a finite group $G$ is a graph having vertex set as $G$ in which two vertices $u$ and $v$ are adjacent if $v=u^m$ or $u=v^n$ for some…

Combinatorics · Mathematics 2025-10-30 Subarsha Banerjee
‹ Prev 1 3 4 5 6 7 10 Next ›