2021/12/23 by Nicolás Bousquet, Bousquet, Nicolas, Quentin Deschamps +5 · 3 citations
Computer Science · #Advanced Graph Theory Research #Graph Labeling and Dimension Problems #Computational Geometry and Mesh Generation
paper · pdf · doi:10.48550/arxiv.2112.12512
Square coloring is a variant of graph coloring where vertices within distance two must receive different colors. When considering planar graphs, the most famous conjecture (Wegner, 1977) states that \frac32Δ+1 colors are sufficient to square color every planar graph of maximum degree Δ. This conjecture has been proven asymptotically for graphs with large maximum degree. We consider here planar graphs with small maximum degree and show that 2Δ+7 colors are sufficient, which improves the best known bounds when 6\leqslant Δ\leqslant 31.