3-dynamic coloring of planar triangulations

Loeb et al. (2018) showed that if G is a planar graph, then χ3d(G)≤10, and there is a planar graph G with χ3d(G)=7. Thus, finding an optimal upper bound on χ3d(G) for a planar graph G is a natural interesting problem. In this paper, we show that χ3d(G)≤5 if G is a planar triangulation. The upper bound is sharp.