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Bibliographic Details
Main Author: Tabachnikov, Serge
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2409.12609
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Table of Contents:
  • An old theorem, due to Graustein, asserts that the average curvature of a plane oval is attained at least at four points. We present a proof by way of wave propagation and extend this result to the spherical and hyperbolic geometries - in the latter case, to horocyclically convex curves only.