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Related papers: Weak Degeneracy of Planar Graphs

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Motivated by the study of greedy algorithms for graph coloring, we introduce a new graph parameter, which we call weak degeneracy. By definition, every $d$-degenerate graph is also weakly $d$-degenerate. On the other hand, if $G$ is weakly…

Combinatorics · Mathematics 2022-11-28 Anton Bernshteyn , Eugene Lee

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…

Combinatorics · Mathematics 2023-03-15 Ming Han , Tao Wang , Jianglin Wu , Huan Zhou , Xuding Zhu

A graph is $k$-degenerate if every subgraph $H$ has a vertex $v$ with $d_{H}(v) \leq k$. The class of degenerate graphs plays an important role in the graph coloring theory. Observed that every $k$-degenerate graph is $(k + 1)$-choosable…

Combinatorics · Mathematics 2023-03-24 Tao Wang

Thomassen showed that planar graphs are 5-list-colourable, and that planar graphs of girth at least five are 3-list-colourable. An easy degeneracy argument shows that planar graphs of girth at least four are 4-list-colourable. In 2022,…

Combinatorics · Mathematics 2025-05-01 Ewan Davies , Evelyne Smith-Roberge

Bernshteyn and Lee defined a new notion, weak degeneracy, which is slightly weaker than the ordinary degeneracy. It is proved that strictly $f$-degenerate transversal is a common generalization of list coloring, $L$-forested-coloring and…

Combinatorics · Mathematics 2022-07-05 Qianqian Wang , Tao Wang , Xiaojing Yang

Motivated by the study of greedy algorithms for graph coloring, Bernshteyn and Lee introduced a generalization of graph degeneracy, which is called weak degeneracy. In this paper, we show the lower bound of the weak degeneracy for…

Combinatorics · Mathematics 2023-10-02 Yuxuan Yang

The \textit{$k$-weak-dynamic number} of a graph $G$ is the smallest number of colors we need to color the vertices of $G$ in such a way that each vertex $v$ of degree $d(v)$ sees at least $\rm{min}\{k,d(v)\}$ colors on its neighborhood. We…

Combinatorics · Mathematics 2018-02-19 Caroline Accurso , Vitaliy Chernyshov , Leaha Hand , Sogol Jahanbekam , Paul Wenger

Weak degeneracy of a graph is a variation of degeneracy that has a close relationship to many graph coloring parameters. In this article, we prove that planar graphs with distance of $3$-cycles at least 2 and no cycles of lengths $5, 6, 7$…

Combinatorics · Mathematics 2025-02-26 Tao Wang , Ya-Nan Wang , Xiaojing Yang

Weak coloring numbers generalize the notion of degeneracy of a graph. They were introduced by Kierstead \& Yang in the context of games on graphs. Recently, several connections have been uncovered between weak coloring numbers and various…

Combinatorics · Mathematics 2022-03-28 Gwenaël Joret , Piotr Micek

The classic upper bound on the chromatic number of $d$-degenerate graphs is $d+1$, shown to be tight by complete graphs. A natural question is whether this bound remains tight if one forbids large cliques. Classic constructions of Tutte and…

Combinatorics · Mathematics 2026-01-22 Domagoj Bradač , Jacob Fox , Raphael Steiner , Benny Sudakov , Shengtong Zhang

In this work, we introduce DPG-coloring using the concepts of DP-coloring and variable degeneracy to modify the proofs on the following papers: (i) DP-3-coloring of planar graphs without $4$, $9$-cycles and cycles of two lengths from $\{6,…

Combinatorics · Mathematics 2019-08-12 Keaitsuda Maneeruk Nakprasit , Kittikorn Nakprasit

A {\em strong edge coloring} of a graph $G$ is a proper edge coloring in which every color class is an induced matching. The {\em strong chromatic index} $\chiup_{s}'(G)$ of a graph $G$ is the minimum number of colors in a strong edge…

Combinatorics · Mathematics 2022-06-13 Tao Wang

A strong edge-coloring of a graph $G$ is an edge-coloring in which every color class is an induced matching, and the strong chromatic index $\chi_s'(G)$ is the minimum number of colors needed in strong edge-colorings of $G$. A graph is…

Combinatorics · Mathematics 2023-01-31 Gexin Yu , Rachel Yu

A defective $k$-coloring is a coloring on the vertices of a graph using colors $1,2, \dots, k$ such that adjacent vertices may share the same color. A $(d_1,d_2)$-\emph{coloring} of a graph $G$ is a defective $2$-coloring of $G$ such that…

Combinatorics · Mathematics 2025-01-14 Pongpat Sittitrai , Wannapol Pimpasalee , Kittikorn Nakprasit

Weak and strong coloring numbers are generalizations of the degeneracy of a graph, where for each natural number $k$, we seek a vertex ordering such every vertex can (weakly respectively strongly) reach in $k$ steps only few vertices with…

Combinatorics · Mathematics 2021-04-08 Zdeněk Dvořák , Jakub Pekárek , Torsten Ueckerdt , Yelena Yuditsky

A hypergraph is "$d$-degenerate" if every subhypergraph has a vertex of degree at most $d$. A greedy algorithm colours every such hypergraph with at most $d+1$ colours. We show that this bound is tight, by constructing an $r$-uniform…

Combinatorics · Mathematics 2014-08-18 David R. Wood

DP-coloring was introduced by Dvo\v{r}\'{a}k and Postle as a generalization of list coloring and signed coloring. A new coloring, strictly $f$-degenerate transversal, is a further generalization of DP-coloring and $L$-forested-coloring. In…

Combinatorics · Mathematics 2025-02-28 Rui Li , Tao Wang

We prove several results on coloring squares of planar graphs without 4-cycles. First, we show that if $G$ is such a graph, then $G^2$ is $(\Delta(G)+72)$-degenerate. This implies an upper bound of $\Delta(G)+73$ on the chromatic number of…

Combinatorics · Mathematics 2021-10-06 Ilkyoo Choi , Daniel W. Cranston , Théo Pierron

A graph $G$ is $k$-degenerate if it can be transformed into an empty graph by subsequent removals of vertices of degree $k$ or less. We prove that every connected planar graph with average degree $d \ge 2$ has a 4-degenerate induced…

Combinatorics · Mathematics 2013-10-07 Robert Lukoťka , Ján Mazák , Xuding Zhu

A graph $G$ is $d$-degenerate if every non-null subgraph of $G$ has a vertex of degree at most $d$. We prove that every $n$-vertex planar graph has a $3$-degenerate induced subgraph of order at least $3n/4$.

Combinatorics · Mathematics 2022-10-05 Y. Gu , H. A. Kierstead , Sang-il Oum , Hao Qi , Xuding Zhu
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