Torsion von Minimalflächen.
The connected components of the zero set of any conformal vector field v, in a pseudo-Riemannian manifold (M, g) of arbitrary signature, are of two types, which may be called ‘essential’ and ‘nonessential’. The former consist of points at which v is essential, that is, cannot be turned into a Killing field by a local conformal change of the metric. In a component of the latter type, points at which v is nonessential form a relatively-open dense subset that is at the same time a totally umbilical...
Nous montrons qu’une surface minimale complété, plongée dans , de courbure totale finie et homéomorphe a moins deux points est l’hélicoïde.