On the first eigenvalue of the Laplacian for compact submanifolds of Euclidean space.
On the first secondary invariant of Molino's central sheaf
For a Riemannian foliation on a closed manifold, the first secondary invariant of Molino's central sheaf is an obstruction to tautness. Another obstruction is the class defined by the basic component of the mean curvature with respect to some metric. Both obstructions are proved to be the same up to a constant, and other geometric properties are also proved to be equivalent to tautness.
On the Floer homology of plumbed three-manifolds.
On the flux homomorphism for regular Poisson manifolds
Author’s abstract: “We introduce the concept of the flux homomorphism for regular Poisson manifolds. First we establish a one-to-one correspondence between Poisson diffeomorphisms close to and closed foliated 1-forms close to 0. This allows to show that the group of Poisson automorphisms is locally contractible and to define the flux locally. Then, by means of the foliated cohomology, we extend this local homomorphism to a global one”.
On the Focal Locus of a Submanifold in a Riemannian Manifold of Constant Sectional Curvature
On the formality of products and wedges
On the four vertex theorem in planes with radial density
It is shown that in a plane with a radial density the four vertex theorem holds for the class of all simple closed curves if and only if the density is constant. On the other hand, for the class of simple closed curves that are invariant under a rotation about the origin, the four vertex theorem holds for every radial density.
On the four-dimensional -manifolds of positive Ricci curvature.
On the four-vertex theorem.
On the functional independence of scalar invariants of curvature for dimensions n=2,3,4
On the Fundamental Group of a Visibility Manifold.
On the Fundamental Group of Non-Positively Curved Manifolds.
On the Fundamental Theorem for Non-Degenerate Complex Affine Hypersurface Immersions.
On the Gauss curvature of maximal surfaces in the 3-dimensional Lorentz-Minkowski space.
On the Gauss image of a spacelike hypersurface with constant mean curvature in Minkowski space.
On the Gauss map of B-scrolls in -dimensional Lorentzian space forms
In this note we show that -scrolls over null curves in a 3-dimensional Lorentzian space form are characterized as the only ruled surfaces with null rulings whose Gauss maps satisfy the condition , being a parallel endomorphism of .
On the Gauss map of complete surfaces of constant mean curvature in R3 and R4.
On the Gauss Map of Surfaces in Rn.
On the Gaussian and mean curvature of certain surfaces.
On the Gauss-Kronecker Curvature Tensors.