English

On the Four Vertex Theorem on planes with radial density $e^{\phi(r)}$

Differential Geometry 2008-01-21 v2

Abstract

It is showed that on a plane with a radial density the Four Vertex Theorem holds for the class of all simple closed curves if and only if the density is constant. But for the class of simple closed curves that are invariant under a rotation about the origin, the Four Vertex Theorem holds for every radial density.

Keywords

Cite

@article{arxiv.0709.1757,
  title  = {On the Four Vertex Theorem on planes with radial density $e^{\phi(r)}$},
  author = {Doan The Hieu and Tran Le Nam},
  journal= {arXiv preprint arXiv:0709.1757},
  year   = {2008}
}

Comments

7 pages, 2figures

R2 v1 2026-06-21T09:16:34.672Z