English

Centered colorings and weak coloring numbers in minor-closed graph classes

Combinatorics 2026-03-16 v1 Discrete Mathematics

Abstract

Let C\mathcal{C} be a proper minor-closed class of graphs. Given the minors excluded in C\mathcal{C}, we determine the maximum qq-centered chromatic number and the maximum qqth weak coloring number of graphs in C\mathcal{C} within an O(q)\mathcal{O}(q)-factor. Moreover, when C\mathcal{C} excludes a planar graph, we determine it within a constant factor. Our results imply that the qq-centered chromatic number of KtK_t-minor-free graphs is in O(qt1)\mathcal{O}(q^{t-1}), improving on the previously known O(qh(t))\mathcal{O}(q^{h(t)}) bound with a large and non-explicit function hh. We include similar bounds for another family of parameters, the fractional treedepth fragility rates. All our bounds are proved via the same general framework.

Keywords

Cite

@article{arxiv.2603.13097,
  title  = {Centered colorings and weak coloring numbers in minor-closed graph classes},
  author = {Jędrzej Hodor and Hoang La and Piotr Micek and Clément Rambaud},
  journal= {arXiv preprint arXiv:2603.13097},
  year   = {2026}
}

Comments

120 pages, 38 figures. Some of the results already appeared in arXiv:2411.02122 and arXiv:2407.04588

R2 v1 2026-07-01T11:18:37.696Z