SECTIONALCURVATURE
Sectional curvature
In Riemannian geometry, the sectional curvature is one of the ways to describe the curvature of Riemannian manifolds. The sectional curvature K depends on a two-dimensional plane σp in the tangent space at p. It is the Gaussian curvature of the surface which has the plane σp as a tangent plane at p, obtained from geodesics which start at p in the directions of σp . The sectional curvature is a smooth real-valued function on the 2-Grassmannian bundle over the manifold.The above text is a snippet from Wikipedia: Sectional curvature
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