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Related papers: Distance Seidel matrix of a connected graph

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Let $G_n$ be a simple graph on $V_n=\{v_1,\dots, v_n\}$. The Seidel matrix $S(G_n)$ of $G_n$ is the $n\times n$ matrix whose $(ij)$'th entry, for $i\neq j$ is $-1$ if $v_i\sim v_j$ and $1$ otherwise, and whose diagonal entries are $0$. We…

Combinatorics · Mathematics 2019-04-11 Douglas Rizzolo

Let $\mathcal{G}$ be the set of simple graphs (or multigraphs) $G$ such that for each $G \in \mathcal{G}$ there exists at least two non-empty disjoint proper subsets $V_{1},V_{2}\subseteq V(G)$ satisfying $V(G)\setminus(V_{1} \cup…

Combinatorics · Mathematics 2018-11-19 Cunxiang Duan , Ligong Wang , Xiangxiang Liu

A graph $G$ is said to be determined by its generalized spectrum (DGS for short) if for any graph $H$, $H$ and $G$ are cospectral with cospectral complements implies that $H$ is isomorphic to $G$. It turns out that whether a graph $G$ is…

Combinatorics · Mathematics 2014-10-22 Wei Wang

The difference graph $D(G)$ of a finite group $G$ is the difference of enhanced power graph of $G$ and power graph of $G$, with all isolated vertices are removed. In this paper we study the connectedness and perfectness of $D(G)$ with…

Combinatorics · Mathematics 2024-08-23 Sucharita Biswas , Peter J. Cameron , Angsuman Das , Hiranya Kishore Dey

Let $G$ be a graph of order $n$ with adjacency matrix $A(G)$. The \textit{energy} of graph $G$, denoted by $\mathcal{E}(G)$, is defined as the sum of absolute value of eigenvalues of $A(G)$. It was conjectured that if $A(G)$ is…

Combinatorics · Mathematics 2022-07-12 Saieed Akbari , Hossein Dabirian , S. Mahmood Ghasemi

A graph $G=(V,E)$ is said to be distance magic if there is a bijection $f$ from a vertex set of $G$ to the first $|V(G)|$ natural numbers such that for each vertex $v$, its weight given by $\sum_{u \in N(v)}f(u)$ is constant, where $N(v)$…

Combinatorics · Mathematics 2024-02-09 Himadri Mukherjee , Ravindra Pawar , Tarkeshwar Singh

In the current work we are concerned with sequences of graphs having a grid geometry, with a uniform local structure in a bounded domain $\Omega\subset {\mathbb R}^d$, $d\ge 1$. When $\Omega=[0,1]$, such graphs include the standard Toeplitz…

Numerical Analysis · Mathematics 2021-11-30 Andrea Adriani , Davide Bianchi , Paola Ferrari , Stefano Serra-Capizzano

Given a positive-weighted simple connected graph with $m$ vertices, labelled by the numbers $1,\ldots,m$, we can construct an $m \times m$ matrix whose entry $(i,j)$, for any $i,j\in\{1,\dots,m\}$, is the minimal weight of a path between…

Combinatorics · Mathematics 2020-03-02 Elena Rubei , Dario Villanis Ziani

Regular and distance-regular characterizations of general graphs are well-known. In particular, the spectral excess theorem states that a connected graph G is distance-regular if and only if its spectral excess (a number that can be…

Combinatorics · Mathematics 2013-09-27 A. Abiad , C. Dalfò , M. A. Fiol

The eccentricity matrix of a simple connected graph G is obtained from the distance matrix of G by retaining the largest non-zero distance in each row and column, and the remaining entries are defined to be zero. A bi-block graph is a…

Combinatorics · Mathematics 2023-09-06 T. Divyadevi , I. Jeyaraman

The spread of a real symmetric matrix is defined as the difference between its largest and smallest eigenvalue. The study of graph-related matrices has attracted considerable attention, leading to a substantial body of findings. In this…

Combinatorics · Mathematics 2025-09-04 Lele Liu , Yi-Zheng Fan , Yi Wang , Wenyan Wang

The newly introduced neighborhood matrix extends the power of adjacency and distance matrices to describe the topology of graphs. The adjacency matrix enumerates which pairs of vertices share an edge and it may be summarized by the degree…

General Mathematics · Mathematics 2016-08-09 Jonathan W. Roginski , Ralucca M. Gera , Erik C. Rye

The $d$-dimensional algebraic connectivity $a_d(G)$ of a graph $G=(V,E)$ is a quantitative measure of its $d$-dimensional rigidity, defined in terms of the eigenvalues of stiffness matrices associated with different embeddings of the graph…

Combinatorics · Mathematics 2025-04-03 Yunseong Jung , Alan Lew

Let $SGL_n(\mathbb{F}_2)$ be the set of all invertible $n\times n$ symmetric matrices over the binary field $\mathbb{F}_2$. Let $\Gamma_n$ be the graph with the vertex set $SGL_n(\mathbb{F}_2)$ where a pair of matrices $\{A,B\}$ form an…

Combinatorics · Mathematics 2024-04-29 Marko Orel , Draženka Višnjić

Given a graph $G$, the Laplacian matrix of $G$, $L(G)$ is the difference of the adjacency matrix $A(G)$ and $\text{Deg}(G)$, where $\text{Deg}(G)$ is the diagonal matrix of vertex degrees. The distance Laplacian matrix $D^L({G})$ is the…

Combinatorics · Mathematics 2026-02-20 Subarsha Banerjee , Soumya Ganguly

Consider two simple graphs, G1 and G2, with their respective vertex sets V(G1) and V(G2). The Kronecker product forms a new graph with a vertex set V(G1) X V(G2). In this new graph, two vertices, (x, y) and (u, v), are adjacent if and only…

Spectral Theory · Mathematics 2024-12-02 Priti Prasanna Mondal , Fouzul Atik

In this article, we analyze the limiting eigenvalue distribution (LED) of random geometric graphs (RGGs). The RGG is constructed by uniformly distributing $n$ nodes on the $d$-dimensional torus $\mathbb{T}^d \equiv [0, 1]^d$ and connecting…

Spectral Theory · Mathematics 2019-10-22 Mounia Hamidouche , Laura Cottatellucci , Konstantin Avrachenkov

The distance eigenvalues of a connected graph $G$ are the eigenvalues of its distance matrix $D(G)$. A graph is called distance integral if all of its distance eigenvalues are integers. Let $n \geq 3$ be an integer. A crown graph $Cr(n)$ is…

Combinatorics · Mathematics 2021-09-09 S. Morteza Mirafzal

In 2024, Gutman et al. \cite{I.Gutman 3} defined a new molecular descriptor called as The Euler-Sombor $(ES)$ index of graph. By using this index we define the Euler-Sombor $(ES)$ matrix of a graph $G$ whoes $(i,j)^{th}$ entry is…

Combinatorics · Mathematics 2025-02-13 Sopan Bansode , Sharad Barde , Ganesh Mundhe

For a graph G, the spectral radius \r{ho}(G) of G is the largest eigenvalue of its adjacency matrix. In this paper, we seek the relationship between \r{ho}(G) and the walks of the subgraphs of G. Especially, if G contains a complete…

Combinatorics · Mathematics 2025-05-27 Wenqian Zhang
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