Results 1 to 10 of about 201,344 (258)

Non-1-Planarity of Lexicographic Products of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
In this paper, we show the non-1-planarity of the lexicographic product of a theta graph and K2. This result completes the proof of the conjecture that a graph G ◦ K2 is 1-planar if and only if G has no edge belonging to two cycles.
Matsumoto Naoki, Suzuki Yusuke
doaj   +2 more sources

Acyclic Chromatic Index of 1-Planar Graphs

open access: yesMathematics, 2022
The acyclic chromatic index χa′(G) of a graph G is the smallest k for which G is a proper edge colorable using k colors. A 1-planar graph is a graph that can be drawn in plane such that every edge is crossed by at most one other edge.
Wanshun Yang   +5 more
doaj   +2 more sources

The structure and the list 3-dynamic coloring of outer-1-planar graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2021
An outer-1-planar graph is a graph admitting a drawing in the plane so that all vertices appear in the outer region of the drawing and every edge crosses at most one other edge.
Yan Li, Xin Zhang
doaj   +1 more source

Correction to: Outer 1-Planar Graphs [PDF]

open access: yesAlgorithmica, 2021
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Auer, Christopher   +6 more
openaire   +1 more source

Improved product structure for graphs on surfaces [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2022
Dujmovi\'c, Joret, Micek, Morin, Ueckerdt and Wood [J. ACM 2020] proved that for every graph $G$ with Euler genus $g$ there is a graph $H$ with treewidth at most 4 and a path $P$ such that $G\subseteq H \boxtimes P \boxtimes K_{\max\{2g,3\}}$. We improve
Marc Distel   +3 more
doaj   +1 more source

Packing Trees into 1-planar Graphs [PDF]

open access: yesJournal of Graph Algorithms and Applications, 2020
We introduce and study the 1-planar packing problem: Given $k$ graphs with $n$ vertices $G_1, \dots, G_k$, find a 1-planar graph that contains the given graphs as edge-disjoint spanning subgraphs. We mainly focus on the case when each $G_i$ is a tree and $k=3$.
Felice De Luca   +8 more
openaire   +2 more sources

Partitioning planar graphs with girth at least 9 into an edgeless graph and a graph with bounded size components

open access: yesMathematical Modelling and Control, 2021
In this paper, we study the problem of partitioning the vertex set of a planar graph with girth restriction into parts, also referred to as color classes, such that each part induces a graph with components of bounded order.
Chunyu Tian, Lei Sun
doaj   +1 more source

Equitable Coloring of IC-Planar Graphs with Girth g ≥ 7

open access: yesAxioms, 2023
An equitable k-coloring of a graph G is a proper vertex coloring such that the size of any two color classes differ at most 1. If there is an equitable k-coloring of G, then the graph G is said to be equitably k-colorable.
Danjun Huang, Xianxi Wu
doaj   +1 more source

Skewness and the crossing numbers of graphs

open access: yesAIMS Mathematics, 2023
The skewness of a graph $ G $, $ sk(G) $, is the smallest number of edges that need to be removed from $ G $ to make it planar. The crossing number of a graph $ G $, $ cr(G) $, is the minimum number of crossings over all possible drawings of $ G $. There
Zongpeng Ding
doaj   +1 more source

Relaxed DP-Coloring and another Generalization of DP-Coloring on Planar Graphs without 4-Cycles and 7-Cycles

open access: yesDiscussiones Mathematicae Graph Theory, 2023
DP-coloring is generalized via relaxed coloring and variable degeneracy in [P. Sittitrai and K. Nakprasit, Su cient conditions on planar graphs to have a relaxed DP-3-coloring, Graphs Combin. 35 (2019) 837–845], [K.M. Nakprasit and K.
Sribunhung Sarawute   +3 more
doaj   +1 more source

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