An equality for the curvature function of a simple and closed curve on the plane

We prove an equality for the curvature function of a simple and closed curve on the plane. This equality leads to another proof of the four-vertex theorem in differential geometry. While examining the regularity assumption on the curve for the equality, we make comments on the relation between the b...

Full description

Saved in:
Bibliographic Details
Main Author: Biao Ou
Format: Article
Language:English
Published: Wiley 2003-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Online Access:http://dx.doi.org/10.1155/S0161171203210371
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We prove an equality for the curvature function of a simple and closed curve on the plane. This equality leads to another proof of the four-vertex theorem in differential geometry. While examining the regularity assumption on the curve for the equality, we make comments on the relation between the boundary regularity of a Riemann mapping and two important subjects, the Schauder theory and the strong maximum principle, for elliptic partial differential equations of second order. We take a note on the curvature function itself in recognizing people's handwriting by a calculating device, as an afterthought on the equality.
ISSN:0161-1712
1687-0425