An Analogue of DP-Coloring for Variable Degeneracy and its Applications

Autor: Sittitrai Pongpat, Nakprasit Kittikorn
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Discussiones Mathematicae Graph Theory, Vol 42, Iss 1, Pp 89-99 (2022)
Druh dokumentu: article
ISSN: 2083-5892
DOI: 10.7151/dmgt.2238
Popis: A graph G is list vertex k-arborable if for every k-assignment L, one can choose f(v) ∈ L(v) for each vertex v so that vertices with the same color induce a forest. In [6], Borodin and Ivanova proved that every planar graph without 4-cycles adjacent to 3-cycles is list vertex 2-arborable. In fact, they proved a more general result in terms of variable degeneracy. Inspired by these results and DP-coloring which is a generalization of list coloring and has become a widely studied topic, we introduce a generalization on variable degeneracy including list vertex arboricity. We use this notion to extend a general result by Borodin and Ivanova. Not only this theorem implies results about planar graphs without 4-cycles adjacent to 3-cycle by Borodin and Ivanova, it also implies other results including a result by Kim and Yu [S.-J. Kim and X. Yu, Planar graphs without 4-cycles adjacent to triangles are DP-4-colorable, Graphs Combin. 35 (2019) 707–718] that every planar graph without 4-cycles adjacent to 3-cycles is DP-4-colorable.
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