sectional curvature उदाहरण वाक्य
उदाहरण वाक्य
- Another consequence of the Geometrisation conjecture is that any closed 3-manifold which admits a Riemannian metric with negative sectional curvatures admits in fact a Riemannian metric with constant sectional curvature-1.
- Let M _ i be a sequence of n dimensional Riemannian manifolds, where \ sec ( M _ i ) denotes the sectional curvature of the " i " th manifold.
- In two dimensions sectional curvature is always pointwise constant since there is only one two-dimensional subspace \ Pi _ p \ subset T _ p M, namely T _ p M.
- The 2 theorem states : a Dehn filling of " M " with each filling slope greater than 2 results in a 3-manifold with a complete metric of negative sectional curvature.
- Moreover, if the diameter is equal to ? / " " k ", then the manifold is isometric to a sphere of a constant sectional curvature " k ".
- If for each point in a connected Riemannian manifold ( of dimension three or greater ) the sectional curvature is independent of the tangent 2-plane, then the sectional curvature is in fact constant on the whole manifold.
- If for each point in a connected Riemannian manifold ( of dimension three or greater ) the sectional curvature is independent of the tangent 2-plane, then the sectional curvature is in fact constant on the whole manifold.
- On the other hand one can fix the bound of sectional curvature and get the diameter going to zero, so the almost-flat manifold is a special case of a collapsing manifold, which is collapsing along all directions.
- If tighter bounds on the sectional curvature are known, then this property generalizes to give a comparison theorem between geodesic triangles in " M " and those in a suitable simply connected space form; see Toponogov's theorem.
- Indeed, if \ xi is a vector of unit length on a Riemannian " n "-manifold, then is precisely times the average value of the sectional curvature, taken over all the 2-planes containing \ xi.