On a variant of dichromatic number for digraphs with prescribed sets of arcs
Abstract
In this paper, we consider a variant of dichromatic number on digraphs with prescribed sets of arcs. Let be a digraph and let be two sets of arcs in . For a subdigraph of , let denote the set of all arcs of . Let be the minimum number of parts in a vertex partition of such that for every , the subdigraph of induced by contains no directed cycle with . For and , is equal to the dichromatic number of . We prove that for every digraph and every tuple of integers with and for each arc of , there exists an integer such that if , then contains a subdigraph isomorphic to a subdivision of in which each arc of is subdivided into a directed path~ such that~. This generalizes a theorem of Steiner [Subdivisions with congruence constraints in digraphs of large chromatic number, arXiv:2208.06358] which corresponds to the case when .
Keywords
Cite
@article{arxiv.2307.05897,
title = {On a variant of dichromatic number for digraphs with prescribed sets of arcs},
author = {O-joung Kwon and Xiaopan Lian},
journal= {arXiv preprint arXiv:2307.05897},
year = {2023}
}
Comments
13 pages, 2 figures