Results 31 to 40 of about 30,213,529 (145)
Drawing Outer 1-planar Graphs with Few Slopes
Journal of Graph Algorithms and Applications, 2015 A graph is outer 1-planar if it admits a drawing where each vertex is on the outer face and each edge is crossed by at most another edge. Outer 1-planar graphs are a superclass of the outerplanar graphs and a subclass of the planar partial 3-trees.
Emilio Di Giacomo +2 more
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Acyclic colouring of 1-planar graphs
Discrete Applied Mathematics, 2001 A graph is said to be 1-planar if it can be embedded into the plane so that each of its edges is crossed by at most one other edge. A coloring of the vertices of a graph is said to be acyclic if every cycle contains at least three colors. The acyclic chromatic number \(a(G)\) of a graph \(G\) is the minimal \(k\) such that \(G\) admits an acyclic \(k\)-
Oleg V. Borodin +3 more
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On Aligned Bar 1-Visibility Graphs
Journal of Graph Algorithms and Applications, 2017 A graph is called a bar 1-visibility graph if its vertices can be represented as horizontal segments, called bars, and each edge corresponds to a vertical line of sight which can traverse another bar.
Franz Brandenburg +2 more
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On total colorings of 1-planar graphs [PDF]
Journal of Combinatorial Optimization, 2013 A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, we confirm the total-coloring conjecture for 1-planar graphs with maximum degree at least 13.
Xin Zhang 0017 +2 more
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A Note on Universal Point Sets for Planar Graphs
Journal of Graph Algorithms and Applications, 2020 We investigate which planar point sets allow simultaneous straight-line embeddings of all planar graphs on a fixed number of vertices. We first show that at least $(1.293-o(1))n$ points are required to find a straight-line drawing of each $n$-vertex ...
Manfred Scheucher +2 more
doaj +1 more source
Tuza's Conjecture for Threshold Graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2022 Tuza famously conjectured in 1981 that in a graph without k+1 edge-disjoint triangles, it suffices to delete at most 2k edges to obtain a triangle-free graph. The conjecture holds for graphs with small treewidth or small maximum average degree, including
Marthe Bonamy +6 more
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Plick Graphs with Crossing Number 1 [PDF]
, 2011 In this paper, we deduce a necessary and sufficient condition for graphs whose plick graphs have crossing number 1. We also obtain a necessary and sufficient condition for plick graphs to have crossing number 1 in terms of forbidden ...
Basavanagoud, B., Kulli, V.R.
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On the size of planarly connected crossing graphs
Journal of Graph Algorithms and Applications, 2018 We prove that if an $n$-vertex graph $G$ can be drawn in the plane such that each pair of crossing edges is independent and there is a crossing-free edge that connects their endpoints, then $G$ has $O(n)$ edges.
Eyal Ackerman +2 more
doaj +1 more source
The Liouville and the intersection properties are equivalent for planar graphs [PDF]
, 2012 It is shown that if a planar graph admits no non-constant bounded harmonic function then the trajectories of two independent simple random walks intersect almost ...
Itai Benjamini +5 more
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Note on improper coloring of $1$-planar graphs [PDF]
, 2019 summary:A graph $G=(V,E)$ is called improperly $(d_1, \dots , d_k)$-colorable if the vertex set $V$ can be partitioned into subsets $V_1, \dots , V_k$ such that the graph $G[V_i]$ induced by the vertices of $V_i$ has maximum degree at most $d_i$ for all $
Yue, Jun, Sun, Lei, Chu, Yanan
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