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Related papers: Resistance distance in connected balanced digraphs

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For a graph $G=(V,E)$, assigning each edge $e\in E$ a weight of a dual number $w(e)=1+\widehat{a}_{e}\varepsilon$, the weighted graph $G^{w}=(V,E,w)$ is called a dual number weighted graph, where $-\widehat{a}_{e}$ can be regarded as the…

Combinatorics · Mathematics 2025-02-20 Yu Li , Lizhu Sun , Changjiang Bu

It is known that every distance-regular digraph is connected and normal. An interesting question is: when is a given connected normal digraph distance-regular? Motivated by this question first we give some characterizations of weakly…

Combinatorics · Mathematics 2013-10-29 G. R. Omidi

Simplifications of a result from a prior paper concerning the electric resistance between points in a distance-regular graph are given. In particular, we prove that the maximal resistance between points is bounded by twice the resistance…

Combinatorics · Mathematics 2013-03-22 Jacobus Koolen , Greg Markowsky

Resistance distance is a novel distance function, also a new intrinsic graph metric, which makes some extensions of ordinary distance. Let On be a linear crossed octagonal graph. Recently, Pan and Li (2018) derived the closed formulas for…

Spectral Theory · Mathematics 2019-05-24 Jing Zhao , Jia-Bao Liu , Sakander Hayat

An antidirected trail in a digraph is a trail (a walk with no arc repeated) in which the arcs alternate between forward and backward arcs. An antidirected path is an antidirected trail where no vertex is repeated. We show that it is…

Combinatorics · Mathematics 2016-05-26 Jorgen Bang-Jensen , Stephane Bessy , Bill Jackson , Matthias Kriesell

Let D be a digraph and C be a cycle in D. For any two vertices x and y in D, the distance from x to y is the minimum length of a path from x to y. We denote the square of Let $D$ be a digraph and $C$ be a cycle in $D$. For any two vertices…

Combinatorics · Mathematics 2024-07-29 Jie Zhang , Zhilan Wang , Jin Yan

Let $D$ be a strongly connected digraph. The average distance $\bar{\sigma}(v)$ of a vertex $v$ of $D$ is the arithmetic mean of the distances from $v$ to all other vertices of $D$. The remoteness $\rho(D)$ and proximity $\pi(D)$ of $D$ are…

Combinatorics · Mathematics 2020-01-29 Jiangdong Ai , Stefanie Gerke , Gregory Gutin , Sonwabile Mafunda

In this note we consider the bent linear 2-tree and provide an explicit formula for the resistance distance $r_{G_n}(1,n)$ between the first and last vertices of the graph. We call the graph $G_n$ with vertex set $V(G_n) = \{ 1, 2, \ldots,…

Combinatorics · Mathematics 2017-12-19 Wayne Barrett , Emily J. Evans , Amanda E. Francis

Let $G$ be a connected graph with vertex set $V(G)=\{v_{1},v_{2},...,v_{n}\}$. The distance matrix $D(G)=(d_{ij})_{n\times n}$ is the matrix indexed by the vertices of $G,$ where $d_{ij}$ denotes the distance between the vertices $v_{i}$…

Combinatorics · Mathematics 2018-01-30 Ruifang Liu , Jie Xue

We consider the graph $G_n$ with vertex set $V(G_n) = \{ 1, 2, \ldots, n\}$ and $\{i,j\} \in E(G_n)$ if and only if $0<|i-j| \leq 2$. We call $G_n$ the straight linear 2-tree on $n$ vertices. Using $\Delta$--Y transformations and identities…

Combinatorics · Mathematics 2017-12-19 Wayne Barrett , Emily J. Evans , Amanda E. Francis

Let $G=(V,E)$ be a finite, combinatorial graph. We define a notion of curvature on the vertices $V$ via the inverse of the resistance distance matrix. We prove that this notion of curvature has a number of desirable properties. Graphs with…

Combinatorics · Mathematics 2023-02-22 Karel Devriendt , Andrea Ottolini , Stefan Steinerberger

For positive integers $j\ge k$, an $L(j,k)$-labeling of a digraph $D$ is a function $f$ from $V(D)$ into the set of nonnegative integers such that $|f(x)-f(y)|\ge j$ if $x$ is adjacent to $y$ in $D$ and $|f(x)-f(y)|\ge k$ if $x$ is of…

Combinatorics · Mathematics 2007-05-23 G. J. Chang , J. -J. Chen , D. Kuo , S. C. Liaw

We study the linearization of a discrete transportation distance between probability distributions on finite weighted graphs originally due to Maas (``Gradient flows of the entropy for finite {M}arkov chains,'' J. Funct. Anal. 261(8), 2011)…

Optimization and Control · Mathematics 2026-04-09 Sawyer Robertson , Zhengchao Wan , Alexander Cloninger

Let $G$ be a simple connected simple graph of order $n$. 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…

Combinatorics · Mathematics 2022-10-20 Saleem Khan , S. Pirzada

Recently, the authors gave Ramsey-type results for the path cover/partition number of graphs. In this paper, we continue the research about them focusing on digraphs, and find a relationship between the path cover/partition number and…

Combinatorics · Mathematics 2021-11-30 Shuya Chiba , Michitaka Furuya

We study directed, weighted graphs $G=(V,E)$ and consider the (not necessarily symmetric) averaging operator $$ (\mathcal{L}u)(i) = -\sum_{j \sim_{} i}{p_{ij} (u(j) - u(i))},$$ where $p_{ij}$ are normalized edge weights. Given a vertex $i…

Spectral Theory · Mathematics 2016-11-10 Xiuyuan Cheng , Manas Rachh , Stefan Steinerberger

In this paper we study the distance Ramsey number $R_{{\it D}}(s,t,d)$. The \textit{distance Ramsey number} $R_{{\it D}}(s,t,d) $ is the minimum number $n$ such that for any graph $ G $ on $ n $ vertices, either $G$ contains an induced $ s…

Combinatorics · Mathematics 2017-12-01 Andrey Kupavskii , Andrei Raigorodskii , Maria Titova

For a connected graph $G$, its resistance distance matrix is denoted by $R(G)$. A graph is called resistance regular if all the row (or column) sums of $R(G)$ are equal. We provide a necessary and sufficient condition for a simple connected…

Combinatorics · Mathematics 2025-06-13 Haritha T , Chithra A

Let $G$ be a simple connected graph with vertex set $V(G)=\{v_{1}, v_{2}, \ldots, v_{n}\}$. The distance $d_G(v_i,v_j)$ between two vertices $v_i$ and $v_j$ of $G$ is the length of a shortest path between $v_i$ and $v_j$. The distance…

Combinatorics · Mathematics 2025-09-17 Kexin Yang , Ligong Wang

The central graph $C(G)$ of a graph $G$ is the graph obtained by inserting a new vertex into each edge of $G$ exactly once and joining all the non-adjacent vertices in $G$. Let $G_1$ and $G_2$ be two vertex disjoint graphs. The central…

Combinatorics · Mathematics 2024-04-10 Haritha T , Chithra A