On Helices in the Euclidean n-Space.
On Hermitian manifold with torsion.
Analytic vector fields in a Hermitian manifold have been studied by various authors [3, 4, 6 & 7]. Boothby [2] and Goldberg [1] extended some of these results to Hermitian manifold with torsion. In this paper we define and study p-pseudo-analytic vector fields, which when p = 1, reduce to analytic vector fields as given in [1] and [2]. A necessary and sufficient condition for a vector field to be covariant (contravariant) p-pseudo-analytic has been obtained and their relationship with p-pseudo-harmonic...
On horizontal and complete lifts from a manifold with -structure to its cotangent bundle.
On infinitesimal isometries of a hypersurface
On infinitesimal isometries of surfaces in
On Interior Branch Points of Minimal Surfaces.
On inversions of van der Grinten projections
Approximately 150 map projections are known, but the inverse forms have been published for only two-thirds of them. This paper focuses on finding the inverse forms of van der Grinten projections I--IV, both by non-linear partial differential equations and by the straightforward inverse of their projection equations. Taking into account the particular cases, new derivations of coordinate functions are also presented. Both the direct and inverse equations have the analytic form, are easy to implement...
On Isometric Immersions of the Hyperbolic Plane Into the Lorentz-Minkowski Space and the Monge-Ampère Equation of a Certain Type.
On Isometrie Immersions between Hyperbolic Spaces.
On isotropic congruences of lines in elliptic three-space.
On kinematics and differential geometry of Euclidean submanifolds.
On L2 and L3.
On Levi-flat hypersurfaces tangent to holomorphic webs
We investigate real analytic Levi-flat hypersurfaces tangent to holomorphic webs. We introduce the notion of first integrals for local webs. In particular, we prove that a -web with finitely many invariant subvarieties through the origin tangent to a Levi-flat hypersurface has a holomorphic first integral.
On l'Hospital-type rules for monotonicity.
On linear functions on the sphere
On Mannheim partner curve in dual space.
On metrics of positive Ricci curvature conformal to
Let be a closed Riemannian manifold and the Euclidean metric. We show that for , is not conformal to a positive Einstein manifold. Moreover, is not conformal to a Riemannian manifold of positive Ricci curvature, through a radial, integrable, smooth function, , for . These results are motivated by some recent questions on Yamabe constants.
On minimal annuli in a slab.
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 surfaces in