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20232026
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14 papers · 1 filter

math.CO2026

Tighter Bounds on the Degree-Truncated Choice Number of Planar Graphs

Huijuan Xu, Huan Zhou, Jialu Zhu +1

Assume is a graph and is a positive integer. Let be defined as . If is -choosable, then we say is degree-truncated…

math.CO2025

Planar graphs without cycles of length 4 or 5 are -DP-colorable

Xiaoyan Xu, Xuding Zhu

It was conjectured by Steinberg in 1976 that planar graphs without cycles of length 4 or 5 are 3-colorable. This conjecture attracted a substantial amount of attention and was fina…

math.CO2025

On Alon-Tarsi orientations of sparse graphs

Eun-Kyung Cho, Ilkyoo Choi, Boram Park +1

Assume is a graph, is a sequence of distinct vertices of , and is an integer sequence with . We say is \emph{$(a_1…

math.CO2025

Degree-truncated choosability of graphs

Huan Zhou, Jialu Zhu, Xuding Zhu

A graph is called degree-truncated -choosable if for every list assignment with for each vertex , is -colourable. Richter asked…

math.CO2025

Indicated list colouring game on graphs

Yangyan Gu, Yiting Jiang, Huan Zhou +2

Given a graph and a list assignment for , the indicated -colouring game on is played by two players: Ann and Ben. In each round, Ann chooses an uncoloured vertex…

math.CO2024

Truncated degree AT-orientations of outerplanar graphs

Chenglong Deng, Xuding Zhu

An AT-orientation of a graph is an orientation of such that the number of even Eulerian sub-digraphs and the number of odd Eulerian sub-digraphs of are distinct. Gi…

math.CO2024

Planar graphs having no cycle of length , or are DP-3-colorable

Ligang Jin, Yingli Kang, Xuding Zhu

The concept of DP-coloring of graphs was introduced by Dvořák and Postle, and was used to prove that planar graphs without cycles of length from to are -choosable. In th…

math.CO2024

Colouring signed analogues of Kneser, Schrijver, and Borsuk graphs

Luis Kuffner, Reza Naserasr, Lujia Wang +3

The Kneser signed graph $\KS(n,k)$, , is the graph whose vertices are signed -subsets of (i.e. -subsets of such that $S\…

math.CO2024

Odd 4-coloring of outerplanar graphs

Masaki Kashima, Xuding Zhu

A proper -coloring of is called an odd coloring of if for every vertex , there is a color that appears at an odd number of neighbors of . This concept was introduc…

math.CO2024

Degree-truncated choosability of planar graphs

Yiting Jiang, Huijuan Xu, Xinbo Xu +1

Assume is a graph and is a positive integer. Let be defined as . If is -choosable, then we say is degree-truncated…

math.CO2023

Disjoint list-colorings for planar graphs

Stijn Cambie, Wouter Cames van Batenburg, Xuding Zhu

One of Thomassen's classical results is that every planar graph of girth at least is 3-choosable. One can wonder if for a planar graph of girth sufficiently large and a …

math.CO2023

Truncated degree DP-colourability of -minor free graphs

On-Hei Solomon Lo, Cheng Wang, Huan Zhou +1

Assume is a graph and is a positive integer. Let from to be defined as is the minimum of and . If is -DP-colourable (respectively, $…

math.CO2023

Sparse critical graphs for defective -coloring

Alexandr Kostochka, Jingwei Xu, Xuding Zhu

A graph is -colorable if its vertices can be partitioned into subsets and so that every vertex in has degree at most and every vertex in $G[V_2]…

math.CO2023

Weak degeneracy of planar graphs and locally planar graphs

Ming Han, Tao Wang, Jianglin Wu +2

Weak degeneracy is a variation of degeneracy which shares many nice properties of degeneracy. In particular, if a graph is weakly -degenerate, then for any -list as…