2024/06/25 by Kengo Aoki, Aoki, Kengo
Computer Science · Engineering · #05C15 #Advanced Graph Theory Research #Combinatorics (math.CO) #Computational Geometry and Mesh Generation #FOS: Mathematics #graph theory and CDMA systems
paper · pdf · doi:10.48550/arxiv.2406.17191
openalex publication_date 2024/06/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A 2-distance k-coloring of a graph G is a proper k-coloring such that any two vertices at distance two or less get different colors. The 2-distance chromatic number of G is the minimum k such that G has a 2-distance k-coloring, denoted by χ2(G). In this paper, we show that χ2(G) ≤ 20 for every planar graph G with maximum degree at most six, which improves a former bound χ2(G) ≤ 21.