Lorentzian isothermic surfaces and Bonnet pairs
Lorentzian surfaces in Lorentz three-space are studied using an indefinite version of the quaternions. A classification theorem for Bonnet pairs in Lorentz three-space is obtained.
Motions in the flag space with spherical trajectories. II: The three-parametric motions. (Bewegungsvorgänge des Flaggenraumes mit sphärischen Bahnen. II: Die dreiparametrigen Bewegungsvorgänge.)
Non-Euclidean geometry and differential equations
In this paper a geometrical link between partial differential equations (PDE) and special coordinate nets on two-dimensional smooth manifolds with the a priori given curvature is suggested. The notion of G-class (the Gauss class) of differential equations admitting such an interpretation is introduced. The perspective of this approach is the possibility of applying the instruments and methods of non-Euclidean geometry to the investigation of differential equations. The equations generated by the...
Null 2-type space-like submanifolds of with normalized parallel mean curvature vector.
Null generalized helices in .
O množině středů křivek konstantní křivosti hyperbolické roviny, které se dotýkají dané křivky konstantní křivosti a přímky
O množině středů křivek konstantní křivosti hyperbolické roviny, které se dotýkají dvou různých křivek konstantní křivosti
Octahedral Noncompact Hyperbolic Space Forms With Finite Volume
On asymptotic properties of maximal tubes and bands in a neighborhood of an isolated singularity in Minkowski space.
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 l'Hospital-type rules for monotonicity.
On some analytical manifolds of constant sectional curvature.
On some special surfaces connected with convex surfaces of the Lobachevskij space.
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 the geodesics of tubular surfaces in Minkowski 3-space.
On the geometry of the space of m-pairs of holomorphic subspaces of the n-dimensional projective space ove r an albebra
On the stability of extremal surfaces for a certain area-type functional.
On the total absolute curvature of closed curves in spheres.