English

Square-like quadrilaterals inscribed in embedded space curves

Differential Geometry 2021-03-26 v1 Geometric Topology

Abstract

The square-peg problem asks if every Jordan curve in the plane has four points which are the vertices of a square. The problem is open for continuous Jordan curves, but it has been resolved for various regularity classes of curves between continuous and C1C^1-smooth Jordan curves. Here, in a generalization of the square-peg problem, we consider embedded curves in space, and ask if they have inscribed quadrilaterals with equal sides and equal diagonals. We call these quadrilaterals "square-like". We give a regularity class (finite total curvature without cusps) in which we can prove that every embedded curve has an inscribed square-like quadrilateral. The key idea is to use local data to show that short enough arcs have small curvature, thus ruling out small squares. This allows us to successfully use a limiting argument on approximating curves.

Keywords

Cite

@article{arxiv.2103.13848,
  title  = {Square-like quadrilaterals inscribed in embedded space curves},
  author = {Jason Cantarella and Elizabeth Denne and John McCleary},
  journal= {arXiv preprint arXiv:2103.13848},
  year   = {2021}
}

Comments

11 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:1402.6174

R2 v1 2026-06-24T00:33:18.555Z