Published March 2026 | Version Published
Journal Article

Big line or big convex polygon

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Stanford University
  • 3. ROR icon Princeton University
  • 4. ROR icon University of Illinois at Chicago
  • 5. ROR icon University of California, San Diego

Abstract

Let ESℓ(n) be the minimum N such that every N-element point set in the plane contains either ℓ collinear members or n points in convex position. We prove that there is a constant C > 0 such that, for each ℓ, n ≥ 3, (3ℓ − 1) ⋅ 2^(n − 5) < ESℓ(n) < ℓ² ⋅ 2^(n + C n log n). A similar extension of the well-known Erdős–Szekeres cups-caps theorem is also proved.

Copyright and License

© 2025 Published by Elsevier B.V.

Acknowledgement

This research was initiated during a visit to the American Institute of Mathematics under their SQuaREs program. We are grateful to Sam Spiro for pointing out a typographical error in a previous version of this paper.

Funding

Research supported by NSF Awards DMS-2054452 and DMS-2348859.
Research supported by NSF Award DMS-2154129.
Research supported by NSF Award DMS-2103154.
Research partially supported by NSF Awards DMS-1952767 and DMS-2153576.
Research supported by an NSF CAREER Award and by NSF Awards DMS-1952786 and DMS-2246847.
Research supported by NSF Award DMS-1800332.

Additional details

Related works

Is new version of
Discussion Paper: arXiv:2405.03455 (arXiv)

Funding

National Science Foundation
DMS-2054452
National Science Foundation
DMS-2348859
National Science Foundation
DMS-2154129
National Science Foundation
DMS-2103154
National Science Foundation
DMS-1952767
National Science Foundation
DMS-2153576
National Science Foundation
DMS-1952786
National Science Foundation
DMS-2246847
National Science Foundation
DMS-1800332

Dates

Accepted
2025-08-20
Available
2025-08-26
Available online
Available
2025-08-28
Version of record

Caltech Custom Metadata

Caltech groups
Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published