English
Related papers

Related papers: Planar graphs as distinguished graph of Morse flow…

200 papers

A graph is IC-planar if it admits a drawing in the plane with at most one crossing per edge and such that two pairs of crossing edges share no common end vertex. IC-planarity specializes both NIC-planarity, which allows a pair of crossing…

Discrete Mathematics · Computer Science 2017-07-28 Christian Bachmaier , Franz J. Brandenburg , Kathrin Hanauer

We prove that every 3-connected 2-indivisible infinite planar graph has a 1-way infinite 2-walk. (A graph is 2-indivisible if deleting finitely many vertices leaves at most one infinite component, and a 2-walk is a spanning walk using every…

Combinatorics · Mathematics 2015-08-28 Daniel P. Biebighauser , M. N. Ellingham

For any chord diagram on a circle there exists a complete graph on sufficiently many vertices such that any generic immersion of it to the plane contains a plane closed curve whose chord diagram contains the given chord diagram as a…

Geometric Topology · Mathematics 2012-10-30 Marisa Sakamoto , Kouki Taniyama

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

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 graph is 1-planar if it can be drawn on the plane so that each edge is crossed by no more than one other edge (and any pair of crossing edges cross only once). A non-1-planar graph $G$ is minimal if the graph $G-e$ is 1-planar for every…

Combinatorics · Mathematics 2011-10-24 Vladimir P. Korzhik , Bojan Mohar

A key concept for many graph layout algorithms is planarity, a graph property that allows to draw vertices and edges crossing-free in the plane. Important is the generalization to $k$-planar graphs, which can be drawn in the plane with at…

Discrete Mathematics · Computer Science 2026-05-18 Aaron Büngener , Jakob Franz , Michael Kaufmann , Maximilian Pfister

To investigate the topological structure of Morse functions on the projective plane we use the Reeb graphs. We describe it properties and prove that it is a complete topological invariant of simple Morse function on $\mathbb{R} P^2$. We…

Geometric Topology · Mathematics 2023-03-08 Svitlana Bilun , Alexandr Prishlyak , Serhii Stas , Alina Vlasenko

The notion of 1-planarity is among the most natural and most studied generalizations of graph planarity. A graph is 1-planar if it has an embedding where each edge is crossed by at most another edge. The study of 1-planar graphs dates back…

Computational Geometry · Computer Science 2017-07-21 Stephen G. Kobourov , Giuseppe Liotta , Fabrizio Montecchiani

The 2-blowup of a graph is obtained by replacing each vertex with two non-adjacent copies; a graph is biplanar if it is the union of two planar graphs. We disprove a conjecture of Gethner that 2-blowups of planar graphs are biplanar:…

Combinatorics · Mathematics 2024-10-29 David Eppstein

In this paper, we study the embedded topology of smooth plane quartics and its bitangent lines via two-graphs and apply it to construct interesting examples for Zariski $m$-ple.

Algebraic Geometry · Mathematics 2019-03-19 Shinzo Bannai , Momoko Yamamoto-Ohno

A graph is \emph{fan-crossing free} if it has a drawing in the plane so that each edge is crossed by independent edges, that is the crossing edges have distinct vertices. On the other hand, it is \emph{fan-crossing} if the crossing edges…

Discrete Mathematics · Computer Science 2020-12-14 Franz J. Brandenburg

For integers $a\ge 2b>0$, a \emph{circular $a/b$-flow} is a flow that takes values from $\{\pm b, \pm(b+1), \dots, \pm(a-b)\}$. The Planar Circular Flow Conjecture states that every $2k$-edge-connected planar graph admits a circular…

Combinatorics · Mathematics 2020-07-14 Daniel W. Cranston , Jiaao Li

In this survey, we explore recent literature on finding the cores of higher graphs using geometric and topological means. We study graphs, hypergraphs, and simplicial complexes, all of which are models of higher graphs. We study the notion…

History and Overview · Mathematics 2025-06-30 Inés García-Redondo , Claudia Landi , Sarah Percival , Anda Skeja , Bei Wang , Ling Zhou

In this paper, we introduce the notion of 2-boundary planar graphs. A graph is 2-boundary planar if it has an embedding in the plane so that all vertices lie on the boundary of at most two faces and no edges are crossed. A proper coloring…

Combinatorics · Mathematics 2025-04-07 Weichan Liu , Mengke Qi , Xin Zhang

A Graph is called 2-self-centered if its diameter and radius both equal to 2. In this paper, we begin characterizing these graphs by characterizing edge-maximal 2-self-centered graphs via their complements. Then we split characterizing…

Combinatorics · Mathematics 2019-10-29 Mohammad Hadi Shekarriz , Madjid Mirzavaziri , Kamyar Mirzavaziri

Many real life networks present an average path length logarithmic with the number of nodes and a degree distribution which follows a power law. Often these networks have also a modular and self-similar structure and, in some cases -…

Statistical Mechanics · Physics 2009-02-26 Alicia Miralles , Lichao Chen , Zhongzhi Zhang , Francesc Comellas

An arithmetical structure on a graph is given by a labeling of the vertices which satisfies certain divisibility properties. In this note, we look at several families of graphs and attempt to give counts on the number of arithmetical…

Combinatorics · Mathematics 2019-03-05 Darren Glass , Joshua Wagner

In order to apply quantum topology methods to nonplanar graphs, we define a planar diagram category that describes the local topology of embeddings of graphs into surfaces. These \emph{virtual graphs} are a categorical interpretation of…

Geometric Topology · Mathematics 2020-05-01 Calvin McPhail-Snyder , Kyle A. Miller

Let a finitely generated group $G$ split as a graph of groups. If edge groups are undistorted and do not contribute to the Morse boundary $\partial_MG$, we show that every connected component of $\partial_MG$ with at least two points…

Group Theory · Mathematics 2022-07-20 Elia Fioravanti , Annette Karrer