English
Related papers

Related papers: A construction of distance cospectral graphs

200 papers

Let $E \subset {\Bbb F}_q^d$, the $d$-dimensional vector space over a finite field with $q$ elements. Construct a graph, called the distance graph of $E$, by letting the vertices be the elements of $E$ and connect a pair of vertices…

Combinatorics · Mathematics 2014-06-03 M. Bennett , J. Chapman , D. Covert , D. Hart , A. Iosevich , J. Pakianathan

A gain graph over a group $G$, also referred to as $G$-gain graph, is a graph where an element of a group $G$, called gain, is assigned to each oriented edge, in such a way that the inverse element is associated with the opposite…

Combinatorics · Mathematics 2023-04-10 Aida Abiad , Francesco Belardo , Antonina P. Khramova

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. The crown graph $Cr(n)$…

Combinatorics · Mathematics 2025-10-23 S. Morteza Mirafzal

Several researchers have recently explored various graph parameters that can or cannot be characterized by the spectrum of a matrix associated with a graph. In this paper we show that several NP-hard zero forcing numbers are not…

Combinatorics · Mathematics 2022-04-25 Aida Abiad , Boris Brimkov , Jane Breen , Thomas R. Cameron , Himanshu Gupta , Ralihe R. Villagrán

Let $\Gamma=\Gamma(A)$ denote a simple strongly connected digraph with vertex set $X$, diameter $D$, and let $\{A_0,A:=A_1,A_2,\ldots,A_D\}$ denote the set of distance-$i$ matrices of $\Gamma$. Let $\{R_i\}_{i=0}^D$ denote a partition of…

Combinatorics · Mathematics 2024-04-08 Giusy Monzillo , Safet Penić

A graph $H$ is an \emph{isometric} subgraph of $G$ if $d_H(u,v)= d_G(u,v)$, for every pair~$u,v\in V(H)$. A graph is \emph{distance preserving} if it has an isometric subgraph of every possible order. A graph is \emph{sequentially distance…

Discrete Mathematics · Computer Science 2025-02-14 Jason P. Smith , Emad Zahedi

We are interested in the general question: to what extent are the spectral properties of a graph connected to the distance function? Our motivation is a concrete example of this question that is due to Steinerberger. We provide some…

Combinatorics · Mathematics 2020-11-19 Kelly B Yancey , Matthew Yancey

Switching is an operation on a graph that does not change the spectrum of the adjacency matrix, thus producing cospectral graphs. An important activity in the field of spectral graph theory is the characterization of graphs by their…

Combinatorics · Mathematics 2025-10-03 Aida Abiad , Nils Van de Berg , Robin Simoens

Let $G$ be a simple connected graph of order $n$ and $D(G)$ be the distance matrix of $G.$ Suppose that $\lambda_{1}(D(G))\geq\lambda_{2}(D(G))\geq\cdots\geq\lambda_{n}(D(G))$ are the distance spectrum of $G$. A graph $G$ is said to be…

Combinatorics · Mathematics 2015-04-17 Ruifang Liu , Jie Xue , Litao Guo

In this paper, we present a new metric distance for comparing two large graphs to find similarities and differences between them based on one of the most important graph structural properties, which is Node Adjacency Information, for all…

Discrete Mathematics · Computer Science 2022-06-14 Arefe Alikhani , Farzad Didehvar

Given a graph $G$, the exponential distance matrix is defined entry-wise by letting the $(u,v)$-entry be $q^{\text{dist}(u,v)}$, where $\text{dist}(u,v)$ is the distance between the vertices $u$ and $v$ with the convention that if vertices…

Combinatorics · Mathematics 2023-03-08 Steve Butler , Elizabeth Coper , Aaron Li , Kate Lorenzen , Zoe Schopick

In this paper, a new measurement to compare two large-scale graphs based on the theory of quantum probability is proposed. An explicit form for the spectral distribution of the corresponding adjacency matrix of a graph is established. Our…

Discrete Mathematics · Computer Science 2018-07-03 Hayoung Choi , Hosoo Lee , Yifei Shen , Yuanming Shi

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

Distance matrices of graphs were introduced by Graham and Pollack in 1971 to study a problem in communications. Since then, there has been extensive research on the distance matrices of graphs -- a 2014 survey by Aouchiche and Hansen on…

Combinatorics · Mathematics 2021-05-06 Leslie Hogben , Carolyn Reinhart

In this paper we compute the spectrum of a special block matrix and use it to describe the distance spectra of some double join of graphs. As an application, we give several families of distance equienergetic graphs of diameter 3.

Combinatorics · Mathematics 2022-09-26 Rakshith B. R. , B. J. Manjunatha

The traditional adjacency matrix of a mixed graph is not symmetric in general, hence its eigenvalues may be not real. To overcome this obstacle, several authors have recently defined and studied various Hermitian adjacency matrices of…

Combinatorics · Mathematics 2022-05-12 Mohammad Abudayah , Omar Alomari , Torsten Sander

In this article, we study Pareto eigenvalues of distance matrix of connected graphs and show that the non zero entries of every distance Pareto eigenvector of a tree forms a strictly convex function on the forest generated by the vertices…

Combinatorics · Mathematics 2018-09-21 Milan Nath , Deepak Sarma

Suppose that $G$ is a connected simple graph with the vertex set $V( G ) = \{ v_1,v_2,\cdots ,v_n \} $. Let $d( v_i,v_j ) $ be the distance between $v_i$ and $v_j$. Then the distance matrix of $G$ is $D( G ) =( d_{ij} )_{n\times n}$, where…

Combinatorics · Mathematics 2020-11-04 Xu Chen , Guoping Wang

Here, the structural symmetries of a hypergraph are represented through equivalence relations on the vertex set of the hypergraph. A matrix associated with the hypergraph may not reflect a specific structural symmetry. In the context of a…

Combinatorics · Mathematics 2025-08-12 Anirban Banerjee , Samiron Parui

A constructive method is given for obtaining cospectral vertices in undirected graphs, along with an operation that preserves this construction. We prove that the construction yields cospectral vertices, as well as strongly cospectral…

Combinatorics · Mathematics 2026-01-07 Onur Ege Erden , Fatihcan M. Atay