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On the geometry of tangent bundles with a class of metrics

Esmaeil Peyghan, Abbas Heydari, Leila Nourmohammadi Far (2012)

Annales Polonici Mathematici

We introduce a class of metrics on the tangent bundle of a Riemannian manifold and find the Levi-Civita connections of these metrics. Then by using the Levi-Civita connection, we study the conformal vector fields on the tangent bundle of the Riemannian manifold. Finally, we obtain some relations between the flatness (resp. local symmetry) properties of the tangent bundle and the flatness (resp. local symmetry) on the base manifold.

On the intrinsic geometry of a unit vector field

Yampolsky, Alexander L. Yampolsky, Alexander L. (2002)

Commentationes Mathematicae Universitatis Carolinae

We study the geometrical properties of a unit vector field on a Riemannian 2-manifold, considering the field as a local imbedding of the manifold into its tangent sphere bundle with the Sasaki metric. For the case of constant curvature K , we give a description of the totally geodesic unit vector fields for K = 0 and K = 1 and prove a non-existence result for K 0 , 1 . We also found a family ξ ω of vector fields on the hyperbolic 2-plane L 2 of curvature - c 2 which generate foliations on T 1 L 2 with leaves of constant intrinsic...

On the Martin compactification of a bounded Lipschitz domain in a riemannian manifold

John C. Taylor (1978)

Annales de l'institut Fourier

The Martin compactification of a bounded Lipschitz domain D R n is shown to be D for a large class of uniformly elliptic second order partial differential operators on D .Let X be an open Riemannian manifold and let M X be open relatively compact, connected, with Lipschitz boundary. Then M is the Martin compactification of M associated with the restriction to M of the Laplace-Beltrami operator on X . Consequently an open Riemannian manifold X has at most one compactification which is a compact Riemannian...

On the nonexistence of stable minimal submanifolds and the Lawson-Simons conjecture

Ze-Jun Hu, Guo-Xin Wei (2003)

Colloquium Mathematicae

Let M̅ be a compact Riemannian manifold with sectional curvature K M ̅ satisfying 1 / 5 < K M ̅ 1 (resp. 2 K M ̅ < 10 ), which can be isometrically immersed as a hypersurface in the Euclidean space (resp. the unit Euclidean sphere). Then there exist no stable compact minimal submanifolds in M̅. This extends Shen and Xu’s result for 1/4-pinched Riemannian manifolds and also suggests a modified version of the well-known Lawson-Simons conjecture.

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