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On the maximum principle for principal curvatures

Nina Ivochkina (1996)

Banach Center Publications

The paper contains the estimates from above of the principal curvatures of the solution to some curvature equations. A correction of the author's previous argument is presented.

On the nonexistence of stable minimal submanifolds and the Lawson-Simons conjecture

Ze-Jun Hu, Guo-Xin Wei (2003)

Colloquium Mathematicae

Let M̅ be a compact Riemannian manifold with sectional curvature K M ̅ satisfying 1 / 5 < K M ̅ 1 (resp. 2 K M ̅ < 10 ), which can be isometrically immersed as a hypersurface in the Euclidean space (resp. the unit Euclidean sphere). Then there exist no stable compact minimal submanifolds in M̅. This extends Shen and Xu’s result for 1/4-pinched Riemannian manifolds and also suggests a modified version of the well-known Lawson-Simons conjecture.

On the quadric CMC spacelike hypersurfaces in Lorentzian space forms

Cícero P. Aquino, Henrique F. de Lima, Fábio R. dos Santos (2016)

Colloquium Mathematicae

We deal with complete spacelike hypersurfaces immersed with constant mean curvature in a Lorentzian space form. Under the assumption that the support functions with respect to a fixed nonzero vector are linearly related, we prove that such a hypersurface must be either totally umbilical or isometric to a hyperbolic cylinder of the ambient space.

On total curvature of immersions and minimal submanifolds of spheres

Giovanni Rotondaro (1993)

Commentationes Mathematicae Universitatis Carolinae

For closed immersed submanifolds of Euclidean spaces, we prove that | μ | 2 d V V / R 2 , where μ is the mean curvature field, V the volume of the given submanifold and R is the radius of the smallest sphere enclosing the submanifold. Moreover, we prove that the equality holds only for minimal submanifolds of this sphere.

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