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Related papers: Equidistant dimension of Johnson and Kneser graphs

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In a graph A, for each two arbitrary vertices g, h with d(g,h)=2,|MAg2h|=mAg2h is introduced the number of edges of A that are closer to g than to h. We say A is a 2-edge distance-balanced graph if we have mAg2h=mAh2g. In this article, we…

Combinatorics · Mathematics 2023-09-07 Zohreh Aliannejadi , Mehdi alaeiyan , Alireza Gilani , Jafar Asadpour

We study some equivalent properties of the curvature-dimension conditions $CD(n,K)$ inequality on infinite, but locally finite graph. These equivalences are gradient estimate, Poincar\'e type inequalities and reverse Poincar\'e…

Combinatorics · Mathematics 2015-12-10 Yong Lin , Shuang Liu

In 2010, Koolen and Bang proposed the following conjecture: For a fixed integer $m \geq 2$, any geometric distance-regular graph with smallest eigenvalue $-m$, diameter $D \geq 3$ and $c_2 \geq 2$ is either a Johnson graph, a Grassmann…

Combinatorics · Mathematics 2026-01-16 Chenhui Lv , Jack H. Koolen

Many applications in pattern recognition represent patterns as a geometric graph. The geometric graph distance (GGD) has recently been studied as a meaningful measure of similarity between two geometric graphs. Since computing the GGD is…

Computational Geometry · Computer Science 2023-06-12 Sushovan Majhi

For an ordered subset $S = \{s_1, s_2,\dots s_k\}$ of vertices and a vertex $u$ in a connected graph $G$, the metric representation of $u$ with respect to $S$ is the ordered $k$-tuple $ r(u|S)=(d_G(v,s_1), d_G(v,s_2),\dots,$ $d_G(v,s_k))$,…

Combinatorics · Mathematics 2015-09-08 Juan A. Rodriguez-Velazquez , Dorota Kuziak , Ismael G. Yero , Jose M. Sigarreta

The notion of metric dimension, $dim(G)$, of a graph $G$, as well as a number of variants, is now well studied. In this paper, we begin a local analysis of this notion by introducing $cdim_G(v)$, \emph{the connected metric dimension of $G$…

Combinatorics · Mathematics 2022-06-30 Linda Eroh , Cong X. Kang , Eunjeong Yi

Let $G$ denote a $Q$-polynomial distance-regular graph with diameter $D$ at least 4. Assume that the intersection numbers of $G$ satisfy $a_i=0$ for $0 \leq i \leq D-1$ and $a_D\neq 0$. We show that $G$ is a polygon, a folded cube, or an…

Combinatorics · Mathematics 2016-09-07 Michael S. Lang , Paul M. Terwilliger

In this paper, we introduce a connection between two classical concepts of graph theory: \; metric dimension and distinguishing number. For a given graph $G$, let ${\rm dim}(G)$ and $D(G)$ represent its metric dimension and distinguishing…

Combinatorics · Mathematics 2023-12-15 Meysam Korivand , Nasrin Soltankhah

We prove a conjecture by Van Dam and Sotirov on the smallest eigenvalue of (distance-$j$) Hamming graphs and a conjecture by Karloff on the smallest eigenvalue of (distance-$j$) Johnson graphs. More generally, we study the smallest…

Combinatorics · Mathematics 2018-04-23 Andries E. Brouwer , Sebastian M. Cioabă , Ferdinand Ihringer , Matt McGinnis

In this paper we introduce a new infinite class of bipartite graphs, called jumped Wenger graphs, which are closely related to Wenger graphs. An tight upper bound of the diameter and the exact girth of a jumped Wenger graph $J_m(q, i, j )$…

Combinatorics · Mathematics 2017-02-13 Li-Ping Wang , Daqing Wan , Weiqiong Wang , Haiyan Zhou

Let $V$ be an $n$-dimensional vector space over a finite field $\mathbb{F}_q$, where $q$ is a prime power. Define the \emph{generalized $q$-Kneser graph} $K_q(n,k,t)$ to be the graph whose vertices are the $k$-dimensional subspaces of $V$…

Combinatorics · Mathematics 2021-01-29 Mengyu Cao , Ke Liu , Mei Lu , Zequn Lv

The exact distance $t$-power of a graph $G$, $G^{[\sharp t]}$, is a graph which has the same vertex set as $G$, with two vertices adjacent in $G^{[\sharp t]}$ if and only if they are at distance exactly $t$ in the original graph $G$. We…

Combinatorics · Mathematics 2024-11-15 Aida Abiad , Afrouz Jabal Ameli , Luuk Reijnders

The problem of determining whether a graph $G$ can be realized as a unit-distance graph in $\mathbb{Z}^2$ is NP-complete. As far as we can tell, a proof of this result has never been written up. We prove NP-completeness of this problem by…

Computational Complexity · Computer Science 2026-05-25 Eric Binnendyk

We investigate the behavior of electric potentials on distance-regular graphs, and extend some results of a prior paper. Our main result, Theorem 4, shows(together with Corollary 3) that if distance is measured by the electric resistance…

Combinatorics · Mathematics 2011-03-16 Jack Koolen , Greg Markowsky , Jongyook Park

The new graph parameter twin-width, introduced by Bonnet, Kim, Thomass e and Watrigant in 2020, allows for an FPT algorithm for testing all FO properties of graphs. This makes classes of efficiently bounded twin-width attractive from the…

Combinatorics · Mathematics 2022-11-08 Jakub Balabán , Petr Hliněný , Jan Jedelský

The famous Erd\H{o}s distinct distances problem asks the following: how many distinct distances must exist between a set of $n$ points in the plane? There are many generalisations of this question that ask one to consider different spaces…

Combinatorics · Mathematics 2025-05-13 Sean Dewar , Nora Frankl , Samuel Mansfield , Anthony Nixon , Jonathan Passant , Audie Warren

Let $G$ be a simple graph and $A(G)$ be the adjacency matrix of $G$. The matrix $S(G) = J -I -2A(G)$ is called the Seidel matrix of $G$, where $I$ is an identity matrix and $J$ is a square matrix all of whose entries are equal to 1.…

Combinatorics · Mathematics 2019-02-05 M. Souri , F. Heydari , M. Maghasedi

The $k$-power hypergraph $G^{(k)}$ is the $k$-uniform hypergraph that is obtained by adding $k-2$ new vertices to each edge of a graph $G$, for $k \geq 3$. A parity-closed walk in $G$ is a closed walk that uses each edge an even number of…

Combinatorics · Mathematics 2023-02-22 Lixiang Chen , Edwin R. van Dam , Changjiang Bu

Given a connected graph $G=(V,E)$ and a vertex set $S\subset V$, the {\em Steiner distance} $d(S)$ of $S$ is the size of a minimum spanning tree of $S$ in $G$. For a connected graph $G$ of order $n$ and an integer $k$ with $2\leq k \leq n$,…

Combinatorics · Mathematics 2020-12-23 Josiah Reiswig

Let $G=(V,E)$ be a connected graph and let $d(u,v)$ denote the distance between vertices $u,v \in V$. A metric basis for $G$ is a set $B\subseteq V$ of minimum cardinality such that no two vertices of $G$ have the same distances to all…

Discrete Mathematics · Computer Science 2018-01-17 Cyriac Grigorious , Thomas Kalinowski , Joe Ryan , Sudeep Stephen
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