English
Related papers

Related papers: Computing crossing numbers with topological and ge…

200 papers

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

We investigate crossing minimization for 1-page and 2-page book drawings. We show that computing the 1-page crossing number is fixed-parameter tractable with respect to the number of crossings, that testing 2-page planarity is…

Data Structures and Algorithms · Computer Science 2018-12-18 Michael J. Bannister , David Eppstein

In this work, we study a mathematically rigorous metric of a graph visualization quality under conditions that relate to visualizing a bipartite graph. Namely we study rectilinear crossing number in a special arrangement of the complete…

Combinatorics · Mathematics 2023-10-25 Mohsen Nafar

In this note we provide an improved upper bound on the biplanar crossing number of the 8-dimensional hypercube. The $k$-planar crossing number of a graph $cr_k(G)$ is the number of crossings required when every edge of $G$ must be drawn in…

Combinatorics · Mathematics 2017-11-06 Gregory Clark , Gwen Spencer

Orienting the edges of an undirected graph such that the resulting digraph satisfies some given constraints is a classical problem in graph theory, with multiple algorithmic applications. In particular, an $st$-orientation orients each edge…

Data Structures and Algorithms · Computer Science 2023-07-11 Carla Binucci , Giuseppe Liotta , Fabrizio Montecchiani , Giacomo Ortali , Tommaso Piselli

We consider the minimization of edge-crossings in geometric drawings of graphs $G=(V, E)$, i.e., in drawings where each edge is depicted as a line segment. The respective decision problem is NP-hard [Bienstock, '91]. In contrast to theory…

Computational Geometry · Computer Science 2019-07-03 Marcel Radermacher , Ignaz Rutter

Tree decompositions of graphs are of fundamental importance in structural and algorithmic graph theory. Planar decompositions generalise tree decompositions by allowing an arbitrary planar graph to index the decomposition. We prove that…

Combinatorics · Mathematics 2007-06-13 David R. Wood , Jan Arne Telle

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 crossing number of a graph $G$ is the least number of crossings over all possible drawings of $G$. We present a structural characterization of graphs with crossing number one.

Combinatorics · Mathematics 2021-08-24 André C. Silva , Alan Arroyo , R. Bruce Richter , Orlando Lee

We study some basic algorithmic problems concerning the intersection of tropical hypersurfaces in general dimension: deciding whether this intersection is nonempty, whether it is a tropical variety, and whether it is connected, as well as…

Combinatorics · Mathematics 2007-05-23 Thorsten Theobald

Let $G$ be a simple topological graph and let $\Gamma$ be a polyline drawing of $G$. We say that $\Gamma$ \emph{partially preserves the topology} of $G$ if it has the same external boundary, the same rotation system, and the same set of…

Computational Geometry · Computer Science 2018-09-24 Emilio Di Giacomo , Peter Eades , Giuseppe Liotta , Henk Meijer , Fabrizio Montecchiani

We introduce the Orchard crossing number, which is defined in a similar way to the well-known rectilinear crossing number. We compute the Orchard crossing number for some simple families of graphs. We also prove some properties of this…

Combinatorics · Mathematics 2009-04-23 Elie Feder , David Garber

The crossing number of a graph $G$ is the minimum number of crossings in a drawing of $G$ in the plane. A rectilinear drawing of a graph $G$ represents vertices of $G$ by a set of points in the plane and represents each edge of $G$ by a…

Combinatorics · Mathematics 2024-02-26 Vida Dujmović , Camille La Rose

Determining unknotting numbers is a large and widely studied problem. We consider the more general question of the unknotting number of a spatial graph. We show the unknotting number of spatial graphs is subadditive. Let $g$ be an embedding…

Geometric Topology · Mathematics 2018-05-03 Dorothy Buck , Danielle O'Donnol

We investigate the problem of drawing graphs in 2D and 3D such that their edges (or only their vertices) can be covered by few lines or planes. We insist on straight-line edges and crossing-free drawings. This problem has many connections…

Computational Geometry · Computer Science 2016-09-02 Steven Chaplick , Krzysztof Fleszar , Fabian Lipp , Alexander Ravsky , Oleg Verbitsky , Alexander Wolff

Determining the crossing numbers of Cartesian products of small graphs with arbitrarily large paths has been an ongoing topic of research since the 1970s. Doing so requires the establishment of coincident upper and lower bounds; the former…

Combinatorics · Mathematics 2024-09-12 Zayed Asiri , Ryan Burdett , Markus Chimani , Michael Haythorpe , Alex Newcombe , Mirko H. Wagner

Given a straight-line drawing of a graph, a segment is a maximal set of edges that form a line segment. Given a planar graph $G$, the segment number of $G$ is the minimum number of segments that can be achieved by any planar straight-line…

Computational Geometry · Computer Science 2024-07-03 Sabine Cornelsen , Giordano Da Lozzo , Luca Grilli , Siddharth Gupta , Jan Kratochvíl , Alexander Wolff

We consider a variant of the clustering problem for a complete weighted graph. The aim is to partition the nodes into clusters maximizing the sum of the edge weights within the clusters. This problem is known as the clique partitioning…

Social and Information Networks · Computer Science 2023-09-15 Alexander Belyi , Stanislav Sobolevsky , Alexander Kurbatski , Carlo Ratti

In communication field, an important issue is to group users and base stations to as many as possible subnetworks satisfying certain interference constraints. These problems are usually formulated as a graph partition problems which…

Combinatorics · Mathematics 2020-09-30 Chicheng Ma , Yucong Tang , Guanghui Wang , Guiying Yan , Bo Bai

The notion of forbidden-transition graphs allows for a robust generalization of walks in graphs. In a forbidden-transition graph, every pair of edges incident to a common vertex is permitted or forbidden; a walk is compatible if all pairs…

Data Structures and Algorithms · Computer Science 2020-09-29 Thomas Bellitto , Shaohua Li , Karolina Okrasa , Marcin Pilipczuk , Manuel Sorge