Strong orientation of a connected graph for a crossing family
Combinatorics
2024-11-21 v1
Abstract
Given a connected graph and a crossing family over ground set such that for every , we prove there exists a strong orientation of for , i.e., an orientation of such that each set in has at least one outgoing and at least one incoming arc. This implies the main conjecture in Chudnovsky et al. (Disjoint dijoins. Journal of Combinatorial Theory, Series B, 120:18--35, 2016). In particular, in every minimal counterexample to the Edmonds-Giles conjecture where the minimum weight of a dicut is , the arcs of nonzero weight must be disconnected.
Keywords
Cite
@article{arxiv.2411.13202,
title = {Strong orientation of a connected graph for a crossing family},
author = {Ahmad Abdi and Mahsa Dalirrooyfard and Meike Neuwohner},
journal= {arXiv preprint arXiv:2411.13202},
year = {2024}
}
Comments
10 pages, 2 figures