Proof of Halin's normal spanning tree conjecture
Combinatorics
2022-07-12 v2
Abstract
Halin conjectured 20 years ago that a graph has a normal spanning tree if and only if every minor of it has countable colouring number. We prove Halin's conjecture. This implies a forbidden minor characterisation for the property of having a normal spanning tree.
Keywords
Cite
@article{arxiv.2005.02833,
title = {Proof of Halin's normal spanning tree conjecture},
author = {Max Pitz},
journal= {arXiv preprint arXiv:2005.02833},
year = {2022}
}
Comments
14 pages