Results 11 to 20 of about 211,073 (326)
Planar Graphs as VPG-Graphs [PDF]
Journal of Graph Algorithms and Applications, 2013 Summary: A graph is \(B_k\)-VPG when it has an intersection representation by paths in a rectangular grid with at most \(k\) bends (turns). It is known that all planar graphs are \(B_3\)-VPG and this was conjectured to be tight. We disprove this conjecture by showing that all planar graphs are \(B_2\)-VPG.
Steven Chaplick, Torsten Ueckerdt
openalex +4 more sources
Weak Degeneracy of Planar Graphs and Locally Planar Graphs
The Electronic Journal of Combinatorics, 2023 Weak degeneracy is a variation of degeneracy which shares many nice properties of degeneracy. In particular, if a graph $G$ is weakly $d$-degenerate, then for any $(d+1)$-list assignment $L$ of $G$, one can construct an $L$ coloring of $G$ by a modified greedy coloring algorithm.
Han, Ming +4 more
openaire +2 more sources
Algebraic & Geometric Topology, 2022 We prove two results on the classification of trivial Legendrian embeddings $g: G \rightarrow (S^3, _{std})$ of planar graphs. First, the oriented Legendrian ribbon $R_g$ and rotation invariant $\text{rot}_g$ are a complete set of invariants. Second, if $G$ is 3-connected or contains $K_4$ as a minor, then the unique trivial embedding of $G$ is ...
Lambert-Cole, Peter, O'Donnol, Danielle
openaire +2 more sources
Planar Projections of Graphs [PDF]
Discrete Applied Mathematics, 2020 We introduce and study a new graph representation where vertices are embedded in three or more dimensions, and in which the edges are drawn on the projections onto the axis-parallel planes. We show that the complete graph on $n$ vertices has a representation in $\lceil \sqrt{n/2}+1 \rceil$ planes.
N.R. Aravind, Udit Maniyar
openaire +3 more sources
Planarity of Streamed Graphs [PDF]
Theoretical Computer Science, 2015 In this paper we introduce a notion of planarity for graphs that are presented in a streaming fashion. A $\textit{streamed graph}$ is a stream of edges $e_1,e_2,...,e_m$ on a vertex set $V$. A streamed graph is $ω$-$\textit{stream planar}$ with respect to a positive integer window size $ω$ if there exists a sequence of planar topological drawings $Γ_i$
Da Lozzo G., Rutter I.
openaire +5 more sources
Wheels in planar graphs and Hajós graphs [PDF]
Journal of Graph Theory, 2021 AbstractIt was conjectured by Hajós that graphs containing no ‐subdivision are 4‐colorable. Previous results show that any possible minimum counterexample to Hajós' conjecture, called Hajós graph, is 4‐connected but not 5‐connected. In this paper, we show that if a Hajós graph admits a 4‐cut or 5‐cut with a planar side then the planar side must be ...
Qiqin Xie +3 more
openaire +2 more sources
Untangling a Planar Graph [PDF]
Discrete & Computational Geometry, 2009 A straight-line drawing $ $ of a planar graph $G$ need not be plane, but can be made so by \emph{untangling} it, that is, by moving some of the vertices of $G$. Let shift$(G, )$ denote the minimum number of vertices that need to be moved to untangle $ $. We show that shift$(G, )$ is NP-hard to compute and to approximate. Our hardness results extend
Xavier Goaoc +5 more
openaire +2 more sources
A Planarity Criterion for Graphs [PDF]
SIAM Journal on Discrete Mathematics, 2015 It is proven that a connected graph is planar if and only if all its cocycles with at least four edges are "grounded" in the graph. The notion of grounding of this planarity criterion, which is purely combinatorial, stems from the intuitive idea that with planarity there should be a linear ordering of the edges of a cocycle such that in the two ...
Došen, Kosta, Petrić, Zoran
openaire +3 more sources
Theoretical Computer Science, 2018 We introduce the family of $k$-gap-planar graphs for $k \geq 0$, i.e., graphs that have a drawing in which each crossing is assigned to one of the two involved edges and each edge is assigned at most $k$ of its crossings. This definition is motivated by applications in edge casing, as a $k$-gap-planar graph can be drawn crossing-free after introducing ...
Sang Won Bae +10 more
openaire +5 more sources
Discrete Applied Mathematics, 2017 A graph is NIC-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 at most one common end vertex. NIC-planarity generalizes IC-planarity, which allows a vertex to be incident to at most one crossing edge, and specializes 1-planarity, which only requires at most one crossing per ...
Bachmaier, Christian +4 more
openaire +5 more sources