English

Variations on the Tait-Kneser theorem

Differential Geometry 2021-06-04 v2 Classical Analysis and ODEs

Abstract

The Tait-Kneser theorem, first demonstrated by Peter G. Tait in 1896, states that the osculating circles along a plane curve with monotone non-vanishing curvature are pairwise disjoint and nested. This note contains a proof of this theorem using the Lorentzian geometry of the space of circles. We show how a similar proof applies to two variations on the theorem, concerning the osculating Hooke and Kepler conics along a plane curve. We also prove a version of the 4-vertex theorem for Kepler conics.

Cite

@article{arxiv.2104.02170,
  title  = {Variations on the Tait-Kneser theorem},
  author = {Gil Bor and Connor Jackman and Serge Tabachnikov},
  journal= {arXiv preprint arXiv:2104.02170},
  year   = {2021}
}

Comments

11 pages, 7 figures. One coauthor added. A new result added, a Keplerian version of the 4 vertex theorem

R2 v1 2026-06-24T00:52:10.935Z