English

Ramsey growth in some NIP structures

Logic 2021-01-27 v3 Combinatorics

Abstract

We investigate bounds in Ramsey's theorem for relations definable in NIP structures. Applying model-theoretic methods to finitary combinatorics, we generalize a theorem of Bukh and Matousek [B. Bukh, J. Matou\v{s}ek. "Erd\H{o}s-Szekeres-type statements: Ramsey function and decidability in dimension 11", Duke Mathematical Journal 163.12 (2014): 2243-2270] from the semialgebraic case to arbitrary polynomially bounded oo-minimal expansions of R\mathbb{R}, and show that it doesn't hold in Rexp\mathbb{R}_{\exp}. This provides a new combinatorial characterization of polynomial boundedness for oo-minimal structures. We also prove an analog for relations definable in PP-minimal structures, in particular for the field of the pp-adics. Generalizing [D. Conlon, J. Fox, J. Pach, B. Sudakov, A. Suk "Ramsey-type results for semi-algebraic relations", Transactions of the American Mathematical Society 366.9 (2014): 5043-5065], we show that in distal structures the upper bound for kk-ary definable relations is given by the exponential tower of height k1k-1.

Keywords

Cite

@article{arxiv.1609.05951,
  title  = {Ramsey growth in some NIP structures},
  author = {Artem Chernikov and Sergei Starchenko and Margaret E. M. Thomas},
  journal= {arXiv preprint arXiv:1609.05951},
  year   = {2021}
}

Comments

v.3 26 pages; Section 5 was expanded, providing a discussion of polynomial boundedness in this setting and generalizing the proof to demonstrate that the result applies to P-minimal expansions of fields including analytic expansions and finite extensions of Q_p; minor corrections and presentation improvements were made throughout the article

R2 v1 2026-06-22T15:54:46.853Z