English
Related papers

Related papers: Interval k-Graphs and Orders

200 papers

The study of nonplanar drawings of graphs with restricted crossing configurations is a well-established topic in graph drawing, often referred to as beyond-planar graph drawing. One of the most studied types of drawings in this area are the…

A graph $G$ is $k$-ordered if for any distinct vertices $v_1, v_2, \ldots, v_k \in V(G)$, it has a cycle through $v_1, v_2, \ldots, v_k$ in order. Let $f(k)$ denote the minimum integer so that every $f(k)$-connected graph is $k$-ordered.…

Combinatorics · Mathematics 2020-01-01 Rose McCarty , Yan Wang , Xingxing Yu

Let $G$ be a simple graph of order $n$ and let $k$ be an integer such that $1\leq k\leq n-1$. The $k$-token graph $G^{\{k\}}$ of $G$ is the graph whose vertices are the $k$-subsets of $V(G)$, where two vertices are adjacent in $G^{\{k\}}$…

Combinatorics · Mathematics 2021-06-18 Luis Enrique Adame , Luis Manuel Rivera , Ana Laura Trujillo-Negrete

We introduce a variation of interval graphs, called veto interval (VI) graphs. A VI graph is represented by a set of closed intervals, each containing a point called a veto mark. The edge $ab$ is in the graph if the intervals corresponding…

An equitable tree-$k$-coloring of a graph is a vertex $k$-coloring such that each color class induces a forest and the size of any two color classes differ by at most one. In this work, we show that every interval graph $G$ has an equitable…

Combinatorics · Mathematics 2020-03-10 Bei Niu , Bi Li , Xin Zhang

We consider the problem of finding small distance-preserving subgraphs of undirected, unweighted interval graphs with $k$ terminal vertices. To start with, we show that finding an optimal distance-preserving subgraph is $\mathsf{NP}$-hard…

Data Structures and Algorithms · Computer Science 2018-09-27 Kshitij Gajjar , Jaikumar Radhakrishnan

A graph is reconstructible if it is determined up to isomorphism by the multiset of its proper induced subgraphs. The reconstruction conjecture postulates that every graph of order at least 3 is reconstructible. We show that interval graphs…

Combinatorics · Mathematics 2026-05-13 Irene Heinrich , Masashi Kiyomi , Yota Otachi , Pascal Schweitzer

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 graph is a cograph if it is $P_4$-free. A $k$-polar partition of a graph $G$ is a partition of the set of vertices of $G$ into parts $A$ and $B$ such that the subgraph induced by $A$ is a complete multipartite graph with at most $k$…

Combinatorics · Mathematics 2017-03-13 Pavol Hell , César Hernández-Cruz , Cláudia Linhares Sales

A graph is $k$-planar $(k \geq 1)$ if it can be drawn in the plane such that no edge is crossed more than $k$ times. A graph is $k$-quasi planar $(k \geq 2)$ if it can be drawn in the plane with no $k$ pairwise crossing edges. The families…

The interval graph for a set of intervals on a line consists of one vertex for each interval, and an edge for each intersecting pair of intervals. A probe interval graph is a variant that is motivated by an application to genomics, where…

Data Structures and Algorithms · Computer Science 2013-07-23 Ross M. McConnell , Yahav Nussbaum

We obtain the scaling limits of random graphs drawn uniformly in three families of intersection graphs: permutation graphs, circle graphs, and unit interval graphs. The two first families typically generate dense graphs, in these cases we…

Probability · Mathematics 2024-02-12 Frédérique Bassino , Mathilde Bouvel , Valentin Féray , Lucas Gerin , Adeline Pierrot

The proper thinness of a graph is an invariant that generalizes the concept of a proper interval graph. Every graph has a numerical value of proper thinness and the graphs with proper thinness~1 are exactly the proper interval graphs. A…

Combinatorics · Mathematics 2025-05-19 Flavia Bonomo-Braberman , Ignacio Maqueda , Nina Pardal

A digraph consisting of a set of vertices $V$ and a set of arcs $E$ is called an interval digraph if there exists a family of closed intervals $\{I_u,J_u\}_{u \in V}$ such that $uv$ is an arc if and only if the intersection of $I_u$ and…

Combinatorics · Mathematics 2026-03-10 Ayelén Alcantar , Flavia Bonomo , Guillermo Durán , Nina Pardal

Consider two horizontal lines in the plane. A pair of a point on the top line and an interval on the bottom line defines a triangle between two lines. The intersection graph of such triangles is called a simple-triangle graph. This paper…

Discrete Mathematics · Computer Science 2016-11-29 Asahi Takaoka

Let k be a natural number. We introduce k-threshold graphs. We show that there exists an O(n^3) algorithm for the recognition of k-threshold graphs for each natural number k. k-Threshold graphs are characterized by a finite collection of…

Combinatorics · Mathematics 2015-03-19 Ling-Ju Hung , Ton Kloks , Fernando Villaamil

A graph is called {\em arc-transitive} (or {\em symmetric}) if its automorphism group has a single orbit on ordered pairs of adjacent vertices, and 2-arc-transitive its automorphism group has a single orbit on ordered paths of length 2. In…

Group Theory · Mathematics 2014-09-30 Marston D. E. Conder , Cai-Heng Li , Primoz Potocnik

A unit cube in $k$ dimensional space (or \emph{$k$-cube} in short) is defined as the Cartesian product $R_1\times R_2\times...\times R_k$ where $R_i$(for $1\leq i\leq k$) is a closed interval of the form $[a_i,a_i+1]$ on the real line. A…

Discrete Mathematics · Computer Science 2008-03-26 L. Sunil Chandran , Mathew C. Francis , Naveen Sivadasan

Intersection graphs are very important in both theoretical as well as application point of view. Depending on the geometrical representation, different type of intersection graphs are defined. Among them interval, circular-arc, permutation,…

Discrete Mathematics · Computer Science 2014-04-23 Madhumangal Pal

Circular-arc graphs are graphs that can be represented as intersection graphs of subpaths of a cycle. Interval graphs are graphs that can be represented as intersection graphs of subpaths of a path. Since cycles are locally paths, every…

Combinatorics · Mathematics 2025-12-23 Tara Abrishami , Sandra Albrechtsen , Nathan Bowler , Paul Knappe , Jana Katharina Nickel