Totally umbilical hypersurfaces of a locally product Riemannian manifold
Totally umbilical hypersurfaces of a locally product Riemannian manifold
Introduction.It is well known that a totally umbilical hypersurface with non-vanishing mean curvature of a Euclidean space is isometric with a sphere.To prove this theorem we use, among others, the fact that in a Euclidean space the mean curvature of a totally umbilical hypersurface is a constant.In more general Riemannian …