English

Almost all 9-regular graphs have a modulo-5 orientation

Combinatorics 2025-04-18 v5

Abstract

In 1972 Tutte famously conjectured that every 4-edge-connected graph has a nowhere zero 3-flow; this is known to be equivalent to every 5-regular, 4-edge-connected graph having an edge orientation in which every in-degree is either 1 or 4. Jaeger conjectured a generalization of Tutte's conjecture, namely, that every 4p+14p+1-regular, 4p4p-edge-connected graph has an edge orientation in which every in-degree is either pp or 3p+13p+1. Inspired by the work of Pralat and Wormald investigating p=1p=1, for p=2p=2 we show this holds asymptotically almost surely for random 9-regular graphs. It follows that the conjecture holds for almost all 9-regular, 8-edge-connected graphs. These results make use of the technical small subgraph conditioning method.

Keywords

Cite

@article{arxiv.2210.12103,
  title  = {Almost all 9-regular graphs have a modulo-5 orientation},
  author = {Michelle Delcourt and Reaz Huq and Pawel Pralat},
  journal= {arXiv preprint arXiv:2210.12103},
  year   = {2025}
}

Comments

final version, 20 pages

R2 v1 2026-06-28T04:12:04.772Z