English

The number of minimal surfaces bounded by Enneper's wire

Differential Geometry 2016-03-01 v4

Abstract

Enneper's wire, the image of the circle of radius RR under Enneper's surface, bounds exactly three minimal surfaces for RR between 1 and 3\sqrt 3, and these three surfaces depend continuously on RR. The other two surfaces (besides Enneper's surface) are absolute minima of area among disk-type surfaces bounded by Enneper's wire. These surfaces each have a unique horizontal tangent plane, whose height can be computed from RR, and they are invariant under reflections in the planes x1=0x_1=0 and x2=0x_2 = 0. These two surfaces have positive second variation of area, and depend continuously on RR. This result solves three open problems from the list in Nitche's 1989 book. Enneper's wire is the only Jordan curve Γ\Gamma bounding more than one minimal surface for which a specific bound on the number of minimal surfaces bounded by Γ\Gamma is known.

Keywords

Cite

@article{arxiv.1506.03064,
  title  = {The number of minimal surfaces bounded by Enneper's wire},
  author = {Michael Beeson},
  journal= {arXiv preprint arXiv:1506.03064},
  year   = {2016}
}

Comments

This paper has been withdrawn by the author. The claim that the surfaces all contain two crossed horizontal lines is actually false. The problems posed by Nitsche remain open