English
Related papers

Related papers: Witness Gabriel Graphs

200 papers

In this paper we consider aspects of geometric observability for hypergraphs, extending our earlier work from the uniform to the nonuniform case. Hypergraphs, a generalization of graphs, allow hyperedges to connect multiple nodes and…

Dynamical Systems · Mathematics 2024-04-12 Joshua Pickard , Cooper Stansbury , Amit Surana , Indika Rajapakse , Anthony Bloch

Obstacle representations of graphs have been investigated quite intensely over the last few years. We focus on graphs that can be represented by a single obstacle. Given a (topologically open) polygon $C$ and a finite set $P$ of points in…

Computational Geometry · Computer Science 2016-09-02 Steven Chaplick , Fabian Lipp , Ji-won Park , Alexander Wolff

$\beta$-skeletons, a prominent member of the neighborhood graph family, have interesting geometric properties and various applications ranging from geographic networks to archeology. This paper focuses on developing a new, more general than…

Computational Geometry · Computer Science 2014-11-21 Mirosław Kowaluk , Gabriela Majewska

Let $q=p^e$, where $p$ is a prime and $e\geq 1$ is an integer. For $m\geq 1$, let $P$ and $L$ be two copies of the $(m+1)$-dimensional vector spaces over the finite field $\mathbb{F}_q$. Consider the bipartite graph $W_m(q)$ with partite…

Combinatorics · Mathematics 2014-02-17 Sebastian M. Cioabă , Felix Lazebnik , Weiqiang Li

For a set W of vertices and a vertex v in a graph G, the k-vector r2(v|W) = (aG(v,w1),...,aG(v,wk)) is the adjacency representation of v with respect to W, where W = {w1,...,wk} and aG(x,y) is the minimum of 2 and the distance between the…

Combinatorics · Mathematics 2021-03-02 Mohsen Jannesari

Using the new framework of graph separations developed recently by Diestel and Oum, we show that there is a natural witness to large branch-width which can be defined in a similar way to a bramble. We also apply our methods to a more recent…

Combinatorics · Mathematics 2015-11-13 Joshua Erde

The power graph of a group $G$, denoted as $P(G)$, constitutes a simple undirected graph characterized by its vertex set $G$. Specifically, vertices $a,b$ exhibit adjacency exclusively if $a$ belongs to the cyclic subgroup generated by $b$…

Group Theory · Mathematics 2024-01-23 Dhawlath. G , Raja. V

In the present article, numerical simulations have been performed to find the bond and site percolation thresholds on two-dimensional Gabriel graphs (GG) for Poisson point processes. GGs belong to the family of proximity graphs and are…

Statistical Mechanics · Physics 2014-06-04 Christoph Norrenbrock

The general position number ${\rm gp}(G)$ of a graph $G$ is the cardinality of a largest set of vertices $S$ such that no element of $S$ lies on a geodesic between two other elements of $S$. The complementary prism $G\overline{G}$ of $G$ is…

Combinatorics · Mathematics 2020-01-08 Neethu P. K. , Ullas Chandran S. V. , Manoj Changat , Sandi Klavžar

The interplay between groups and graphs have been the most famous and productive area of algebraic graph theory. In this paper, we introduce and study the graphs whose vertex set is group G such that two distinct vertices a and b having…

Combinatorics · Mathematics 2019-01-01 Shafiq Ur Rehman , Abdul Qudair Baig , Muhammad Imran , Zia Ullah Khan

A point visibility graph is a graph induced by a set of points in the plane where the vertices of the graph represent the points in the point set and two vertices are adjacent if and only if no other point from the point set lies on the…

Discrete Mathematics · Computer Science 2018-05-17 Anne-Sophie Himmel , Clemens Hoffmann , Pascal Kunz , Vincent Froese , Manuel Sorge

In this paper, we focus on a generalised version of Gabriel graphs known as Locally Gabriel graphs ($LGGs$) and Unit distance graphs ($UDGs$) on convexly independent point sets. $UDGs$ are sub graphs of $LGGs$. We give a simpler proof for…

Discrete Mathematics · Computer Science 2017-04-24 Abhijeet Khopkar

Delaunay and Gabriel graphs are widely studied geometric proximity structures. Motivated by applications in wireless routing, relaxed versions of these graphs known as \emph{Locally Delaunay Graphs} ($LDGs$) and \emph{Locally Gabriel…

Computational Geometry · Computer Science 2012-07-03 Abhijeet Khopkar , Sathish Govindarajan

Many real-world networks of interest are embedded in physical space. We present a new random graph model aiming to reflect the interplay between the geometries of the graph and of the underlying space. The model favors configurations with…

Probability · Mathematics 2017-06-14 Jean-Christophe Mourrat , Daniel Valesin

Let G be a cubic graph, with girth at least five, such that for every partition X,Y of its vertex set with |X|,|Y|>6 there are at least six edges between X and Y. We prove that if there is no homeomorphic embedding of the Petersen graph in…

Combinatorics · Mathematics 2014-03-11 Neil Robertson , Paul Seymour , Robin Thomas

A $t$-bar visibility representation of a graph assigns each vertex up to $t$ horizontal bars in the plane so that two vertices are adjacent if and only if some bar for one vertex can see some bar for the other via an unobstructed vertical…

Combinatorics · Mathematics 2019-04-19 Yuanrui Feng , Douglas B. West , Yan Yang

A graph $G$ is cordial if there exists a function $f$ from the vertices of $G$ to $\{0,1\}$ such that the number of vertices labelled $0$ and the number of vertices labelled $1$ differ by at most $1$, and if we assign to each edge $xy$ the…

Combinatorics · Mathematics 2025-03-04 Anand Brahmbhatt , Kartikeya Rai , Amitabha Tripathi

Let $G$ be a non-Engel group and let $L(G)$ be the set of all left Engel elements of $G$. Associate with $G$ a graph $\mathcal{E}_G$ as follows: Take $G\backslash L(G)$ as vertices of $\mathcal{E}_G$ and join two distinct vertices $x$ and…

Group Theory · Mathematics 2007-08-16 Alireza Abdollahi

In a proximity region graph ${\cal G}$ in $\mathbb{R}^d$, two distinct points $x,y$ of a point process $\mu$ are connected when the 'forbidden region' $S(x,y)$ these points determine has empty intersection with $\mu$. The Gabriel graph,…

Probability · Mathematics 2019-09-25 Larry Goldstein , Tobias Johnson , Raphaël Lachièze-Rey

Intuitively speaking, a bipartite graph is mirror if it can be drawn in the Cartesian plane in such a way that, the vertices of one stable are points in x=0, the vertices of the other stable set are points in x=1, the edges are straight…

Combinatorics · Mathematics 2013-12-13 Susana-Clara López , Francesc-Antoni Muntaner-Batle