English

Erd\H{o}s - Szekeres Theorem for Lines

Metric Geometry 2015-04-20 v2 Combinatorics

Abstract

According to the Erd\H{o}s-Szekeres theorem, for every nn, a sufficiently large set of points in general position in the plane contains nn in convex position. In this note we investigate the line version of this result, that is, we want to find nn lines in convex position in a sufficiently large set of lines that are in general position. We prove almost matching upper and lower bounds for the minimum size of the set of lines in general position that always contains nn in convex position. This is quite unexpected, since in the case of points, the best known bounds are very far from each other. We also establish the dual versions of many variants and generalizations of the Erd\H os-Szekeres theorem.

Keywords

Cite

@article{arxiv.1307.5666,
  title  = {Erd\H{o}s - Szekeres Theorem for Lines},
  author = {Imre Bárány and Edgardo Roldán-Pensado and Géza Tóth},
  journal= {arXiv preprint arXiv:1307.5666},
  year   = {2015}
}
R2 v1 2026-06-22T00:55:20.170Z