Hopf hypersurfaces in nearly Kaehler 6-sphere.
Hopf structures on the Borel subalgebra of
Horizons in five-dimensional theory
Horizontal and contact forms on constraint manifolds
Horizontal and vertical geodesics in the Riemann space
Horizontal forms of Chern type on complex Finsler bundles.
Horizontal lift of symmetric connections to the bundle of volume forms ν
In this paper we present the horizontal lift of a symmetric affine connection with respect to another affine connection to the bundle of volume forms ν and give formulas for its curvature tensor, Ricci tensor and the scalar curvature. Next, we give some properties of the horizontally lifted vector fields and certain infinitesimal transformations. At the end, we consider some substructures of a F(3, 1)-structure on ν.
Horizontal lift of tensor fields of type (1,1) from a manifold to its tangent bundle of higher order
Horizontal lifts and foliations
Horizontal lifts of tensor fields and connections to the tangent bundle of higher order
Horizontal maps with homogeneity condition
Horizontal structures on fibre manifolds
Hörmander systems and harmonic morphisms
Given a Hörmander system on a domain we show that any subelliptic harmonic morphism from into a -dimensional riemannian manifold is a (smooth) subelliptic harmonic map (in the sense of J. Jost & C-J. Xu, [9]). Also is a submersion provided that and has rank . If (the Heisenberg group) and , where is the Lewy operator, then a smooth map is a subelliptic harmonic morphism if and only if is a harmonic morphism, where is the canonical circle bundle and is the Fefferman...
Horoballs in simplices and Minkowski spaces.
Horospheres and the Stable Part of the Geodesic Flow.
How Charles Ehresmann's vision of geometry developed with time
In the mid fifties, Charles Ehresmann defined Geometry as "the theory of more or less rich structures, in which algebraic and topological structures are generally intertwined". In 1973 he defined it as the theory of differentiable categories, their actions and their prolongations. Here we explain how he progressively formed this conception, from homogeneous spaces to locally homogeneous spaces, to fibre bundles and foliations, to a general notion of local structures, and to a new foundation of differential...
How many are affine connections with torsion
The question how many real analytic affine connections exist locally on a smooth manifold of dimension is studied. The families of general affine connections with torsion and with skew-symmetric Ricci tensor, or symmetric Ricci tensor, respectively, are described in terms of the number of arbitrary functions of variables.
How to blow infinitely large soap bubbles with a fixed boundary
How to Conjugate C1-Close Group Actions.
How to produce a Ricci flow via Cheeger–Gromoll exhaustion
We prove short time existence for the Ricci flow on open manifolds of non-negative complex sectional curvature without requiring upper curvature bounds. By considering the doubling of convex sets contained in a Cheeger–Gromoll convex exhaustion and solving the singular initial value problem for the Ricci flow on these closed manifolds, we obtain a sequence of closed solutions of the Ricci flow with non-negative complex sectional curvature which subconverge to a Ricci flow on the open manifold. Furthermore,...