English

Linking number and folded ribbon unknots

Geometric Topology 2025-09-24 v1

Abstract

We study Kauffman's model of folded ribbon knots: knots made of a thin strip of paper folded flat in the plane. The folded ribbonlength is the length to width ratio of such a folded ribbon knot. The folded ribbon knot is also a framed knot, and the ribbon linking number is the linking number of the knot and one boundary component of the ribbon. We find the minimum folded ribbonlength for 33-stick unknots with ribbon linking numbers ±1\pm1 and ±3\pm 3, and we prove that the minimum folded ribbonlength for nn-gons with obtuse interior angles is achieved when the nn-gon is regular. Among other results, we prove that the minimum folded ribbonlength of any folded ribbon unknot which is a topological annulus with ribbon linking number ±n\pm n is bounded from above by 2n2n.

Keywords

Cite

@article{arxiv.2208.03239,
  title  = {Linking number and folded ribbon unknots},
  author = {Elizabeth Denne and Troy Larsen},
  journal= {arXiv preprint arXiv:2208.03239},
  year   = {2025}
}

Comments

36 pages, 21 figures

R2 v1 2026-06-25T01:30:59.110Z