Backward Arcs in Hamilton Oriented Cycles and Paths in Directed Graphs with Independence Number Two
Combinatorics
2026-03-25 v1 Discrete Mathematics
Abstract
In a digraph , an oriented path is a sequence of distinct vertices such that either or or both for every . If in , then is a forward arc of ; otherwise, is a backward arc. The independence number is the maximum integer such that has a set of vertices where there is no arc between any pair of vertices. A digraph is -connected if its underlying undirected graph is -connected. Freschi and Lo (JCT-B 2024) proved that every -vertex oriented graph with minimum degree has a Hamilton oriented cycle with at most backward arcs. We prove that every 2-connected digraph with has a Hamilton oriented cycle with at most five backward arcs, and every 1-connected digraph with has a Hamilton oriented path with at most two backward arcs.
Keywords
Cite
@article{arxiv.2603.22993,
title = {Backward Arcs in Hamilton Oriented Cycles and Paths in Directed Graphs with Independence Number Two},
author = {S. Gerke and Q. Guo and G. Gutin and Y. Hao and W. Veeranonchai and A. Yeo},
journal= {arXiv preprint arXiv:2603.22993},
year = {2026}
}