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Related papers: Triple crossing numbers of graphs

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In this paper, we give definitions of three kinds of minimal charts, and we investigate properties of minimal charts and establish fundamental theorems characterizing minimal charts. To classify charts with two or three crossings we use the…

Geometric Topology · Mathematics 2017-04-05 Teruo Nagase , Akiko Shima

We compute the Orchard crossing number, which is defined in a similar way to the rectilinear crossing number, for the complete bipartite graphs K_{n,n}.

Combinatorics · Mathematics 2010-08-17 Elie Feder , David Garber

The crossing number of a graph $G$ denotes the minimum number of crossings in any planar drawing of $G$. In this short note, we confirm a long-standing conjecture posed by Pach, Spencer, and T\'oth over 25 years ago, establishing an optimal…

Combinatorics · Mathematics 2025-02-05 Kaizhe Chen , Jie Ma

We define the crossing number for an embedding of a graph G into R^3, and prove a lower bound on it which almost implies the classical crossing lemma. We also give sharp bounds on the space crossing numbers of pseudo-random graphs.

Combinatorics · Mathematics 2011-08-16 Boris Bukh , Alfredo Hubard

In this paper, we find the crossing number of the complete multipartite graphs $K_{1,1,1,1,n}$, $K_{1,2,2,n}$, $K_{1,1,1,2,n}$ and $K_{1,4,n}$.

Combinatorics · Mathematics 2013-10-17 Pak Tung Ho

An overlap representation is an assignment of sets to the vertices of a graph in such a way that two vertices are adjacent if and only if the sets assigned to them overlap. The overlap number of a graph is the minimum number of elements…

Discrete Mathematics · Computer Science 2010-08-17 Bill Rosgen , Lorna Stewart

Traditionally, knot theorists have considered projections of knots where there are two strands meeting at every crossing. A triple crossing is a crossing where three strands meet at a single point, such that each strand bisects the…

Geometric Topology · Mathematics 2018-05-14 Daishiro Nishida

The crossing number ${\mbox {cr}}(G)$ of a graph $G=(V,E)$ is the smallest number of edge crossings over all drawings of $G$ in the plane. For any $k\ge 1$, the $k$-planar crossing number of $G$, ${\mbox {cr}}_k(G)$, is defined as the…

We study the 1-planar, quasi-planar, and fan-planar crossing number in comparison to the (unrestricted) crossing number of graphs. We prove that there are $n$-vertex 1-planar (quasi-planar, fan-planar) graphs such that any 1-planar…

Computational Geometry · Computer Science 2019-09-10 Markus Chimani , Philipp Kindermann , Fabrizio Montecchiani , Pavel Valtr

A graph is near-planar if it can be obtained from a planar graph by adding an edge. We show the surprising fact that it is NP-hard to compute the crossing number of near-planar graphs. A graph is 1-planar if it has a drawing where every…

Computational Geometry · Computer Science 2012-03-28 Sergio Cabello , Bojan Mohar

A quadruple crossing is a crossing in a projection of a knot or link that has four strands of the knot passing straight through it. A quadruple crossing projection is a projection such that all of the crossings are quadruple crossings. In a…

Geometric Topology · Mathematics 2019-02-20 Colin Adams

Research about crossings is typically about minimization. In this paper, we consider \emph{maximizing} the number of crossings over all possible ways to draw a given graph in the plane. Alpert et al. [Electron. J. Combin., 2009] conjectured…

Computational Geometry · Computer Science 2017-05-16 Markus Chimani , Stefan Felsner , Stephen Kobourov , Torsten Ueckerdt , Pavel Valtr , Alexander Wolff

A graph is crossing-critical if the removal of any of its edges decreases its crossing number. This work is motivated by the following question: to what extent is crossing- criticality a property that is inherent to the structure of a…

Combinatorics · Mathematics 2011-12-20 Laurent Beaudou , César Hernández-Vélez , Gelasio Salazar

Computing the crossing number of a graph is one of the most classical problems in computational geometry. Both it and numerous variations of the problem have been studied, and overcoming their frequent computational difficulty is an active…

Computational Geometry · Computer Science 2024-12-18 Thekla Hamm , Fabian Klute , Irene Parada

Motivated by a problem asked by Richter and by the long standing Harary-Hill conjecture, we study the relation between the crossing number of a graph $G$ and the crossing number of its cone $CG$, the graph obtained from $G$ by adding a new…

Combinatorics · Mathematics 2016-08-30 Carlos A. Alfaro , Alan Arroyo , Marek Derunár , Bojan Mohar

A graph is periodic if it can be obtained by joining identical pieces in a cyclic fashion. It is shown that the limit crossing number of a periodic graph is computable. This answers a question of Benny Pinontoan and Bruce Richter (2004).

Combinatorics · Mathematics 2014-05-21 Zdenek Dvorak , Bojan Mohar

In this paper, we introduce the following new concept in graph drawing. Our task is to find a small collection of drawings such that they all together satisfy some property that is useful for graph visualization. We propose investigating a…

Computational Geometry · Computer Science 2025-09-23 Petr Hliněný , Tomáš Masařík

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…

The {\it crossing number} of a graph $G$ is the minimum number of pairwise intersections of edges in a drawing of $G$. In this paper, we study the crossing numbers of $K_{m}\times P_n$ and $K_{m}\times C_n$.

Discrete Mathematics · Computer Science 2012-11-21 Yuansheng Yang , Baigong Zheng , Xirong Xu , Xiaohui Lin

In 2015, Cartwright et al. showed that any $3$-regular metric graph arises as the skeleton of a tropical plane curve with nodes allowed. They introduced the tropical crossing number of a metric graph as the minimum number of nodes required…

Combinatorics · Mathematics 2025-08-21 Noah Cape , Ralph Morrison