On 2-distance (Δ + 4)-coloring of Planar Graphs with girth Five
摘要
A vertex coloring of a graph G is called a 2-distance coloring if any two vertices at distance at most 2 from each other receive different colors. Let G be a planar graph with girth at least five and maximum degree Δ. We prove that G admits a 2-distance coloring with Δ + 4 colors when Δ ≥ 22, which improves a result of Dong and Lin (Discrete Appl. Math. 217: 495–505, 2017).