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The distance matrix of a graph $G$ is the matrix containing the pairwise distances between vertices. The distance eigenvalues of $G$ are the eigenvalues of its distance matrix and they form the distance spectrum of $G$. We determine the…

The eccentricity matrix of a connected graph $G$ is obtained from the distance matrix of $G$ by retaining the largest distances in each row and each column, and setting the remaining entries as $0$. In this article, a conjecture about the…

Combinatorics · Mathematics 2020-08-18 Iswar Mahato , R. Gurusamy , M. Rajesh Kannan , S. Arockiaraj

Let $G$ be a connected simple graph with $n$ vertices. The distance Laplacian matrix $D^{L}(G)$ is defined as $D^L(G)=Diag(Tr)-D(G)$, where $Diag(Tr)$ is the diagonal matrix of vertex transmissions and $D(G)$ is the distance matrix of $G$.…

Combinatorics · Mathematics 2022-02-18 Saleem Khan , S. Pirzada

Let $D(G)$ denote the distance matrix of a connected graph $G$ with $n$ vertices. The distance spectral gap of a graph $G$ is defined as $\delta_{D^G} = \rho_1 - \rho_2$, where $\rho_1$ and $\rho_2$ represent the largest and second largest…

Combinatorics · Mathematics 2025-02-12 Haritha T , Chithra A.

Resistance distance has been studied extensively in the past years, with the majority of previous studies devoted to undirected networks, in spite of the fact that various realistic networks are directed. Although several generalizations of…

Networking and Internet Architecture · Computer Science 2023-02-09 Mingzhe Zhu , Liwang Zhu , Huan Li , Wei Li , Zhongzhi Zhang

Let $G$ be a finite non abelian group. The centralizer graph of $G$ is a simple undirected graph $\Gamma_{cent}(G)$, whose vertex set consists of proper centralizers of $G$ and two vertices are adjacent if and only if their cardinalities…

Combinatorics · Mathematics 2022-08-03 Jharna Kalita , Somnath Paul

It is well known that the complete multipartite graphs can not be determined by their adjacency spectra. But in this paper, we prove that they can be determined by their distance spectra, which confirms the conjecture proposed by Lin, Hong,…

Combinatorics · Mathematics 2013-07-24 Ya-Lei Jin , Xiao-Dong Zhang

We consider a primitive distance-regular graph $\Gamma$ with diameter at least $3$. We use the intersection numbers of $\Gamma$ to find a positive semidefinite matrix $G$ with integer entries. We show that $G$ has determinant zero if and…

Combinatorics · Mathematics 2017-06-13 Supalak Sumalroj

The distance ideals of graphs are algebraic invariants that generalize the Smith normal form (SNF) and the spectrum of several distance matrices associated with a graph. In general, distance ideals are not monotone under taking induced…

A $\Gamma$-distance magic labeling of a graph $G=(V,E)$ with $|V | = n$ is a bijection $\ell$ from $V$ to an Abelian group $\Gamma$ of order $n$ such that the weight $w(x)=\sum_{y\in N_G(x)}\ell(y)$ of every vertex $x \in V$ is equal to the…

Combinatorics · Mathematics 2017-12-04 Sylwia Cichacz

Temporal graphs are commonly used to represent time-resolved relations between entities in many natural and artificial systems. Many techniques were devised to investigate the evolution of temporal graphs by comparing their state at…

Social and Information Networks · Computer Science 2024-11-20 Lorenzo Dall'Amico , Alain Barrat , Ciro Cattuto

In this paper, we present two new matrices, namely the resistance Laplacian and resistance signless Laplacian matrix of a connected graph. We provide a generalized form of these matrices for different classes of graphs, including the…

Combinatorics · Mathematics 2024-01-30 Shivani Tushar Parab , Raisa DSouza

We study maximal distances in the commuting graphs of matrix algebras defined over algebraically closed fields. In particular, we show that the maximal distance can be attained only between two nonderogatory matrices. We also describe…

Rings and Algebras · Mathematics 2010-09-29 Gregor Dolinar , Bojan Kuzma , Polona Oblak

We show that large subsets of vector spaces over finite fields determine certain point configurations with prescribed distance structure. More specifically, we consider the complete graph with vertices as the points of $A \subseteq…

Combinatorics · Mathematics 2018-02-20 Alex Iosevich , Hans Parshall

The normalized distance Laplacian matrix $\mathcal{D}^{\mathcal{L}}(G)$ of a graph $G$ is a natural generalization of the normalized Laplacian matrix, arising from the matrix of pairwise distances between vertices rather than the adjacency…

Combinatorics · Mathematics 2025-03-17 John Byrne , Jacob Johnston , Carl Schildkraut , Michael Tait

Density matrices of graphs are combinatorial laplacians normalized to have trace one (Braunstein \emph{et al.} \emph{Phys. Rev. A,} \textbf{73}:1, 012320 (2006)). If the vertices of a graph are arranged as an array, then its density matrix…

Computational Complexity · Computer Science 2008-07-03 Roland Hildebrand , Stefano Mancini , Simone Severini

Let G be a graph on n vertices. The Laplacian matrix of G, denoted by L(G), is defined as L(G) = D(G) - A(G), where A(G) is the adjacency matrix of G and D(G) is the diagonal matrix of the vertex degrees of G. A graph G is said to be…

Combinatorics · Mathematics 2020-09-28 Anderson Fernandes Novanta , Carla S. Oliveira , Leonardo S. de Lima

An association scheme is $P$-polynomial if and only if it consists of the distance matrices of a distance-regular graph. Recently, bivariate $P$-polynomial association schemes of type $(\alpha,\beta)$ were introduced by Bernard et al., and…

Combinatorics · Mathematics 2024-01-30 Pierre-Antoine Bernard , Nicolas Crampe , Luc Vinet , Meri Zaimi , Xiaohong Zhang

The enhanced power graph of a group $G$ is a simple undirected graph with vertex set $G$ and two vertices are adjacent if they belong to same cyclic subgroup. In this paper, we study distant properties and detour distant properties such as…

Group Theory · Mathematics 2021-08-31 Parveen , Sandeep Dalal , Jitender Kumar

For a connected graph $G$ of order $n$, let $Diag(Tr)$ be the diagonal matrix of vertex transmissions and $D(G)$ be the distance matrix of $G$. The distance Laplacian matrix of $G$ is defined as $D^L(G)=Diag(Tr)-D(G)$ and the eigenvalues of…

Combinatorics · Mathematics 2022-02-15 S. Pirzada , Saleem Khan