English
Related papers

Related papers: Intersection Graphs: An Introduction

200 papers

We study subclasses of grid intersection graphs from the perspective of order dimension. We show that partial orders of height two whose comparability graph is a grid intersection graph have order dimension at most four. Starting from this…

Combinatorics · Mathematics 2015-12-09 Steven Chaplick , Stefan Felsner , Udo Hoffmann , Veit Wiechert

Chord diagrams on circles and their intersection graphs (also known as circle graphs) have been intensively studied, and have many applications to the study of knots and knot invariants, among others. However, chord diagrams on more general…

Combinatorics · Mathematics 2007-05-23 Thomas Fleming , Blake Mellor

Intersection graphs of geometric objects have been extensively studied, both due to their interesting structure and their numerous applications; prominent examples include interval graphs and permutation graphs. In this paper we study a…

Data Structures and Algorithms · Computer Science 2014-01-29 George B. Mertzios

The L-intersection graphs are the graphs that have a representation as intersection graphs of axis parallel shapes in the plane. A subfamily of these graphs are {L, |, --}-contact graphs which are the contact graphs of axis parallel L, |,…

Computational Geometry · Computer Science 2017-07-31 Daniel Gonçalves , Lucas Isenmann , Claire Pennarun

Metric graphs are often introduced based on combinatorics, upon "associating" each edge of a graph with an interval; or else, casually "gluing" a collection of intervals at their endpoints in a network-like fashion. Here we propose an…

Combinatorics · Mathematics 2021-03-17 Delio Mugnolo

Graph theory provides fundamental concepts for many fields of science like statistical physics, network analysis and theoretical computer science. Here we give a pedagogical introduction to graph theory, divided into three sections. In the…

Disordered Systems and Neural Networks · Physics 2007-05-23 Alexander K. Hartmann , Martin Weigt

An interval graph is considered improper if and only if it has a representation such that an interval contains another interval. Previously these have been investigated in terms of balance and minimal forbidden interval subgraphs for the…

Combinatorics · Mathematics 2015-05-28 Jeffrey J. Beyerl , Wayne Wallace

We give a complete characterization of mixed unit interval graphs, the intersection graphs of closed, open, and half-open unit intervals of the real line. This is a proper superclass of the well known unit interval graphs. Our result solves…

Combinatorics · Mathematics 2014-06-12 Felix Joos

In this paper, we study arrangements of orthogonal circles, that is, arrangements of circles where every pair of circles must either be disjoint or intersect at a right angle. Using geometric arguments, we show that such arrangements have…

Computational Geometry · Computer Science 2019-08-27 Steven Chaplick , Henry Förster , Myroslav Kryven , Alexander Wolff

A string graph is an intersection graph of curves in the plane. A $k$-string graph is a graph with a string representation in which every pair of curves intersects in at most $k$ points. We introduce the class of $(=k)$-string graphs as a…

Combinatorics · Mathematics 2023-08-31 Petr Chmel , Vít Jelínek

The class of intersection bigraphs of unit intervals of the real line whose ends may be open or closed is called a class of mixed unit interval bigraphs. This class of bigraphs is a strict superclass of the class of unit interval bigraphs.…

Discrete Mathematics · Computer Science 2026-05-27 Ashok Kumar Das , Rajkamal Sahu , Amina Khatun

Graphs are nowadays ubiquitous in the fields of signal processing and machine learning. As a tool used to express relationships between objects, graphs can be deployed to various ends: I) clustering of vertices, II) semi-supervised…

Machine Learning · Computer Science 2020-07-17 Carlos Lassance , Vincent Gripon , Gonzalo Mateos

Let $G$ be a finite group. The intersection graph of $G$ is a graph whose vertex set is the set of all proper non-trivial subgroups of $G$ and two distinct vertices $H$ and $K$ are adjacent if and only if $H\cap K \neq \{e\}$, where $e$ is…

Combinatorics · Mathematics 2021-01-01 Sanhan Khasraw

We describe the missing class of the hierarchy of mixed unit interval graphs, generated by the intersection graphs of closed, open and one type of half-open intervals of the real line. This class lies strictly between unit interval graphs…

Discrete Mathematics · Computer Science 2017-02-22 Alexandre Talon , Jan Kratochvíl

We unify several seemingly different graph and digraph classes under one umbrella. These classes are all broadly speaking different generalizations of interval graphs, and include, in addition to interval graphs, also adjusted interval…

Discrete Mathematics · Computer Science 2018-06-28 Pavol Hell , Jing Huang , Ross M. McConnell , Arash Rafiey

Using a notation of corner between edges when graph has a fixed rotation, i.e. cyclical order of edges around vertices, we define combinatorial objects - combinatorial maps as pairs of permutations, one for vertices and one for faces.…

Combinatorics · Mathematics 2009-09-02 Dainis Zeps

We obtain a coarse relationship between geometric intersection numbers of curves and the sum of their subsurface projection distances with explicit quasi-constants. By using this relationship, we give applications in the studies of the…

Geometric Topology · Mathematics 2017-09-12 Yohsuke Watanabe

We derive various inequalities involving the intersection number of the curves contained in geodesics and tight geodesics in the curve graph. While there already exist such inequalities on tight geodesics, our method applies in the setting…

Geometric Topology · Mathematics 2016-03-14 Yohsuke Watanabe

An interval $k$-graph is the intersection graph of a family $\mathcal{I}$ of intervals of the real line partitioned into at most $k$ classes with vertices adjacent if and only if their corresponding intervals intersect and belong to…

Combinatorics · Mathematics 2016-03-01 David E. Brown , Breeann M. Flesch , Larry J. Langley

A path graph is the intersection graph of paths in a tree. A directed path graph is the intersection graph of paths in a directed tree. Even if path graphs and directed path graphs are characterized very similarly, their recognition…

Data Structures and Algorithms · Computer Science 2025-05-07 Lorenzo Balzotti