English

On kernels by rainbow paths in arc-coloured digraphs

Combinatorics 2018-07-24 v1

Abstract

In 2018, Bai, Fujita and Zhang (\emph{Discrete Math.} 2018, 341(6): 1523-1533) introduced the concept of a kernel by rainbow paths (for short, RP-kernel) of an arc-coloured digraph DD, which is a subset SS of vertices of DD such that (aa) there exists no rainbow path for any pair of distinct vertices of SS, and (bb) every vertex outside SS can reach SS by a rainbow path in DD. They showed that it is NP-hard to recognize wether an arc-coloured digraph has a RP-kernel and it is NP-complete to decided wether an arc-coloured tournament has a RP-kernel. In this paper, we give the sufficient conditions for the existence of a RP-kernel in arc-coloured unicyclic digraphs, semicomplete digraphs, quasi-transitive digraphs and bipartite tournaments, and prove that these arc-coloured digraphs have RP-kernels if certain "short" cycles and certain "small" induced subdigraphs are rainbow.

Cite

@article{arxiv.1807.08286,
  title  = {On kernels by rainbow paths in arc-coloured digraphs},
  author = {Ruijuan Li and Yanqin Cao},
  journal= {arXiv preprint arXiv:1807.08286},
  year   = {2018}
}
R2 v1 2026-06-23T03:09:53.579Z