English

A note on the pyjama problem

Combinatorics 2020-05-04 v1 Metric Geometry

Abstract

This note concerns the so-called pyjama problem, whether it is possible to cover the plane by finitely many rotations of vertical strips of half-width ε\varepsilon. We first prove that there exist no periodic coverings for ε<1/3\varepsilon<1/3. Then we describe an explicit (non-periodic) construction for ε=1/31/48\varepsilon =1/3-1/48. Finally, we use a compactness argument combined with some ideas from additive combinatorics to show that a finite covering exists for ε=1/5\varepsilon =1/5. The question whether ε\varepsilon can be arbitrarily small remains open.

Keywords

Cite

@article{arxiv.1211.6138,
  title  = {A note on the pyjama problem},
  author = {R. D. Malikiosis and M. Matolcsi and I. Z. Ruzsa},
  journal= {arXiv preprint arXiv:1211.6138},
  year   = {2020}
}

Comments

9 pages

R2 v1 2026-06-21T22:44:28.312Z