On ends of degree $\omega_1$
Logic
2024-11-11 v1 Combinatorics
Abstract
We prove that if is a semi-special tree that is not special, then there exists a graph , formed as an inflation of a sparse -graph, such that for any special tree , is not a subdivision of an inflation of an sparse -graph. Furthermore has an end of uncountable degree that has no ray graph. This result provides a consistent negative answer to a problem posed by Stefan Geschke et al. in 2023. Additionally, we introduce and explore a property that generalizes Halin's grid theorem, extending it to ends of degree , which was originally established for ends of countable degree.
Keywords
Cite
@article{arxiv.2411.05241,
title = {On ends of degree $\omega_1$},
author = {Leandro Aurichi and Gabriel Fernandes and Paulo Magalhães Júnior},
journal= {arXiv preprint arXiv:2411.05241},
year = {2024}
}