Hadamard manifold
In mathematics, a Hadamard manifold, named after Jacques Hadamard — more often called a Cartan–Hadamard manifold, after Élie Cartan — is a Riemannian manifold that is complete and simply connected and has everywhere non-positive sectional curvature.[1][2] By Cartan–Hadamard theorem all Cartan–Hadamard manifolds are diffeomorphic to the Euclidean space Furthermore it follows from the Hopf–Rinow theorem that every pairs of points in a Cartan–Hadamard manifold may be connected by a unique geodesic segment. Thus Cartan–Hadamard manifolds are some of the closest relatives of
Examples
The Euclidean space with its usual metric is a Cartan–Hadamard manifold with constant sectional curvature equal to
Standard -dimensional hyperbolic space is a Cartan–Hadamard manifold with constant sectional curvature equal to
Properties
In Cartan-Hadamard manifolds, the map is a diffeomorphism for all
See also
- Cartan–Hadamard conjecture
- Cartan–Hadamard theorem – On the structure of complete Riemannian manifolds of non-positive sectional curvature
- Hadamard space – geodesically complete metric space of non-positive curvature
References
- Li, Peter (2012). Geometric Analysis. Cambridge University Press. p. 381. doi:10.1017/CBO9781139105798. ISBN 9781107020641.
- Lang, Serge (1989). Fundamentals of Differential Geometry, Volume 160. Springer. pp. 252–253. ISBN 9780387985930.