English

Spiraling and Folding: The Topological View

Combinatorics 2024-06-11 v1 Computational Geometry

Abstract

For every nn, we construct two curves in the plane that intersect at least nn times and do not form spirals. The construction is in three stages: we first exhibit closed curves on the torus that do not form double spirals, then arcs on the torus that do not form spirals, and finally pairs of planar arcs that do not form spirals. These curves provide a counterexample to a proof of Pach and T\'{o}th concerning string graphs.

Keywords

Cite

@article{arxiv.2206.07849,
  title  = {Spiraling and Folding: The Topological View},
  author = {Jan Kynčl and Marcus Schaefer and Eric Sedgwick and Daniel Štefankovič},
  journal= {arXiv preprint arXiv:2206.07849},
  year   = {2024}
}

Comments

23 pages, 18 figures

R2 v1 2026-06-24T11:53:05.124Z