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arXiv · 2005.02833

Proof of Halin's normal spanning tree conjecture

Max Pitz
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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.

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Max Pitz. 2022-07-11. Proof of Halin's normal spanning tree conjecture. https://arxiv.org/abs/2005.02833

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