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arXiv · 2112.06333

Single-conflict colorings of degenerate graphs

Peter Bradshaw·Tomáš Masařík
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Abstract

We consider the single-conflict coloring problem, a graph coloring problem in which each edge of a graph receives a forbidden ordered color pair. The task is to find a vertex coloring such that no two adjacent vertices receive a pair of colors forbidden at an edge joining them. We show that for any assignment of forbidden color pairs to the edges of a $d$-degenerate graph $G$ on $n$ vertices of edge-multiplicity at most $\log \log n$, $O(\sqrt{ d } \log n)$ colors are always enough to color the vertices of $G$ in a way that avoids every forbidden color pair. This answers a question of Dvo\v{r}\'ak, Esperet, Kang, and Ozeki for simple graphs (Journal of Graph Theory 2021).

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Peter Bradshaw, Tomáš Masařík. 2021-12-12. Single-conflict colorings of degenerate graphs. https://doi.org/10.1002/jgt.23025 10.5817/cz.muni.eurocomb23-028

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