Oriented chromatic number of Halin graphs
arXiv:1307.4901 · doi:10.1016/j.ipl.2013.09.011
Abstract
Oriented chromatic number of an oriented graph is the minimum order of an oriented graph such that admits a homomorphism to . The oriented chromatic number of an unoriented graph is the maximal chromatic number over all possible orientations of . In this paper, we prove that every Halin graph has oriented chromatic number at most 8, improving a previous bound by Hosseini Dolama and Sopena, and confirming the conjecture given by Vignal.