English

Quantitative pyjama

Dynamical Systems 2025-10-21 v1 Combinatorics Number Theory

Abstract

The "pyjama stripe" with parameter ε>0\varepsilon>0 is the set E(ε)E(\varepsilon) of all complex numbers zz such that the distance from (z)\Re(z) to the nearest integer is at most ε\varepsilon. The Pyjama Problem of Iosevich, Kolountzakis, and Matolcsi asks whether, for every choice of ε>0\varepsilon>0, it is possible to cover the entire complex plane with finitely many rotations of E(ε)E(\varepsilon) around the origin. Manners obtained an affirmative answer to this question by studying a ×2,×3\times 2, \times 3-type problem over a suitable solenoid. Manners's argument provided no quantitative bounds (in terms of ε\varepsilon) on the number of rotations required, and Green has highlighted the problem of obtaining such quantitative bounds. Our main result is that expexpexp(εO(1))\exp\exp\exp(\varepsilon^{-O(1)}) rotations of E(ε)E(\varepsilon) suffice to cover the complex plane. Our analysis makes use of the entropic tools developed by Bourgain, Lindenstrauss, Michel, and Venkatesh for quantitative ×2,×3\times 2, \times 3-type results.

Keywords

Cite

@article{arxiv.2510.17744,
  title  = {Quantitative pyjama},
  author = {Noah Kravitz and James Leng},
  journal= {arXiv preprint arXiv:2510.17744},
  year   = {2025}
}

Comments

29 pages, comments welcome!

R2 v1 2026-07-01T06:48:02.906Z