DP-4-coloring of planar graphs with some restrictions on cycles
arXiv:1909.08511 · doi:10.1016/j.disc.2021.112568
Abstract
DP-coloring was introduced by Dvořák and Postle as a generalization of list coloring. It was originally used to solve a longstanding conjecture by Borodin, stating that every planar graph without cycles of lengths 4 to 8 is 3-choosable. In this paper, we give three sufficient conditions for a planar graph to be DP-4-colorable. Actually all the results (Theorem 1.3, 1.4 and 1.7) are stated in the ``color extendability'' form, and uniformly proved by vertex identification and discharging method.
13 pages, 5 figures. arXiv admin note: text overlap with arXiv:1908.04902