Further progress on Wojda's conjecture
Combinatorics
2026-01-21 v1
Abstract
Two digraphs of order are said to pack if they can be found as edge-disjoint subgraphs of the complete digraph of order . It is well established that if the sum of the sizes of the two digraphs is at most , then they pack, with this bound being sharp. However, it is sufficient for the size of the smaller digraph to be only slightly below for the sum of their sizes to significantly exceed this threshold while still guaranteeing the existence of a packing. In 1985, Wojda conjectured that for any , if one digraph has size at most and the other has size less than , then the two digraphs pack. It was previously known that this conjecture holds for . In this paper, we confirm it for and .
Keywords
Cite
@article{arxiv.2601.13085,
title = {Further progress on Wojda's conjecture},
author = {Maciej Cisiński and Andrzej Żak},
journal= {arXiv preprint arXiv:2601.13085},
year = {2026}
}