English

The density of planar sets avoiding unit distances

Metric Geometry 2024-06-25 v3

Abstract

By improving upon previous estimates on a problem posed by L. Moser, we prove a conjecture of Erd\H{o}s that the density of any measurable planar set avoiding unit distances cannot exceed 1/41/4. Our argument implies the upper bound of 0.24700.2470.

Keywords

Cite

@article{arxiv.2207.14179,
  title  = {The density of planar sets avoiding unit distances},
  author = {Gergely Ambrus and Adrián Csiszárik and Máté Matolcsi and Dániel Varga and Pál Zsámboki},
  journal= {arXiv preprint arXiv:2207.14179},
  year   = {2024}
}

Comments

24 pages, 6 figures. Final version, to appear in Mathematical Programming

R2 v1 2026-06-25T01:18:31.533Z