English

A Topological Rainbow Ramsey Theorem

Logic 2026-05-11 v2

Abstract

We show that it is consistent relative to the existence of suitable large cardinals that for any countable-to-one coloring c:[ω2]2ω2c: [\omega_2]^2\to \omega_2, there exists a closed subset Aω2A\subseteq \omega_2 of order type ω1\omega_1 such that c[A]2c\restriction [A]^2 is injective. This theorem simultaneously strengthens two theorems, one by Abraham, Cummings and Smyth and another one by Garti and Zhang, as well as answers a question raised by Garti and Zhang. New combinatorial principles involving towers of countable elementary submodels, games concerning regressive functions and variants of strong Chang's conjecture, which are key elements of the proof, are investigated.

Keywords

Cite

@article{arxiv.2605.03828,
  title  = {A Topological Rainbow Ramsey Theorem},
  author = {Hannes Jakob and Jing Zhang},
  journal= {arXiv preprint arXiv:2605.03828},
  year   = {2026}
}

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33 Pages, comments are welcome!

R2 v1 2026-07-01T12:50:57.196Z