On homogeneous hypersurfaces in complex Grassmannians.
On Instability of Yang-Mills Connections.
On isometric immersions into complex space forms.
On Isometric Immersions of the Hyperbolic Plane Into the Lorentz-Minkowski Space and the Monge-Ampère Equation of a Certain Type.
On level hypersurfaces of the complete lift of a submersion.
On local isometric immersions into complex and quaternionic projective spaces
We will prove that if an open subset of is isometrically immersed into , with , then the image is totally geodesic. We will also prove that if an open subset of isometrically immersed into , with , then the image is totally geodesic.
On minimal generic submanifolds immersed in
We give a pinching theorem for a compact minimal generic submanifold with flat normal connection immersed in an odd-dimensional sphere with standard Sasakian structure.
On minimal homothetical hypersurfaces
We give a classification of minimal homothetical hypersurfaces in an (n+1)-dimensional Euclidean space. In fact, when n ≥ 3, a minimal homothetical hypersurface is a hyperplane, a quadratic cone, a cylinder on a quadratic cone or a cylinder on a helicoid.
On minimal immersions of into
On normal sections of Stiefel submanifold.
On Ricci curvature of -totally real submanifolds in Sasakian space forms.
On Ricci curvature of totally real submanifolds in a quaternion projective space
Let be a Riemannian -manifold. Denote by and the Ricci tensor and the maximum Ricci curvature on , respectively. In this paper we prove that every totally real submanifolds of a quaternion projective space satisfies , where and are the square mean curvature function and metric tensor on , respectively. The equality holds identically if and only if either is totally geodesic submanifold or and is totally umbilical submanifold. Also we show that if a Lagrangian submanifold of...
On some generalisations of constant mean curvature surfaces.
On some generic minimal submanifolds of an odd-dimensional sphere
On Spacelike Hypersurfaces with Constant Mean Curvature in the de Sitter Space.
On stability of minimal submanifolds in compact symmetric spaces
On stable currents in positively pinched curved hypersurfaces
Let Mⁿ (n ≥ 3) be an n-dimensional complete hypersurface in a real space form N(c) (c ≥ 0). We prove that if the sectional curvature of M satisfies the following pinching condition: , where δ = 1/5 for n ≥ 4 and δ = 1/4 for n = 3, then there are no stable currents (or stable varifolds) in M. This is a positive answer to the well-known conjecture of Lawson and Simons.
On submanifolds of two manifolds.
On superminimal surfaces
Using the Cartan method O. Boruvka (see [B1], [B2]) studied superminimal surfaces in four-dimensional space forms. In particular, he described locally the family of all superminimal surfaces and classified all of them with a constant radius of the indicatrix. We discuss the mentioned results from the point of view of the twistor theory, providing some new proofs. It turns out that the superminimal surfaces investigated by geometers at the beginning of this century as well as by O. Boruvka...
On Symmetrie Submanifolds of Spaces of Constant Curvature.