Polynomial bounds for centered colorings on proper minor-closed graph classes
نویسندگان
چکیده
For p∈N, a coloring λ of the vertices graph G is p-centered if for every connected subgraph H G, either receives more than p colors under or there color that appears exactly once in H. Centered colorings play an important role theory sparse classes introduced by Nešetřil and Ossona de Mendez [31], [32], as they structurally characterize bounded expansion — one key sparsity notions this theory. More precisely, class graphs C has only function f:N→N such G∈C p∈N admits with at most f(p) colors. Unfortunately, known proofs existence yield large upper bounds on f governing number needed, even simple planar graphs. In paper, we prove Kt-minor-free O(pg(t)) some g. special case embeddable fixed surface Σ show it O(p19) colors, degree polynomial independent genus Σ. This provides first needed drawn from proper minor-closed classes, which answers open problem posed Dvořák [1]. As algorithmic application, use our main result to graphs, then given n vertices, respectively, where G∈C, can be decided whether time 2O(plogp)⋅nO(1) space nO(1).
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 2021
ISSN: ['0095-8956', '1096-0902']
DOI: https://doi.org/10.1016/j.jctb.2021.06.002