On existence of spacelike surfaces with prescribed boundary.
We study special -planar mappings between two -dimensional (pseudo-) Riemannian manifolds. In 2003 Topalov introduced -projectivity of Riemannian metrics, . Later these mappings were studied by Matveev and Rosemann. They found that for they are projective. We show that -projective equivalence corresponds to a special case of -planar mapping studied by Mikeš and Sinyukov (1983) and -planar mappings (Mikeš, 1994), with . Moreover, the tensor is derived from the tensor and the non-zero...
We see how the first jet bundle of curves into affine space can be realized as a homogeneous space of the Galilean group. Cartan connections with this model are precisely the geometric structure of second-order ordinary differential equations under time-preserving transformations - sometimes called KCC-theory. With certain regularity conditions, we show that any such Cartan connection induces “laboratory” coordinate systems, and the geodesic equations in this coordinates form a system of second-order...
We characterize generalized Douglas-Weyl Randers metrics in terms of their Zermelo navigation data. Then, we study the Randers metrics induced by some important classes of almost contact metrics. Furthermore, we construct a family of generalized Douglas-Weyl Randers metrics which are not -quadratic. We show that the Randers metric induced by a Kenmotsu manifold is a Douglas metric which is not of isotropic -curvature. We show that the Randers metric induced by a Kenmotsu or Sasakian manifold is...
In this paper there are discussed the geodesic mappings which preserved the Einstein tensor. We proved that the tensor of concircular curvature is invariant under Einstein tensor-preserving geodesic mappings.
We develop an algebraic version of Cartan’s method of equivalence or an analog of Tanaka prolongation for the (extrinsic) geometry of curves of flags of a vector space W with respect to the action of a subgroup G of GL(W). Under some natural assumptions on the subgroup G and on the flags, one can pass from the filtered objects to the corresponding graded objects and describe the construction of canonical bundles of moving frames for these curves in the language of pure linear algebra. The scope...