Coloring of Triangle-Free Graphs on the Double Torus

We show that every triangle-free graph on the double torus is 4-colorable. This settles a problem raised by Gimbel and Thomassen [Trans. Amer. Math. Soc. 349 (1997), 4555

• Type: Journal
• Year: 2008
• Where: SIAMDM
• Authors: Daniel Král, Matej Stehlík
• Keywords: Double Torus, Gimbel, SIAMDM 2008, Triangle-free Graph