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sectional curvature (Definition)

Let $ M$ be a Riemannian manifold. Let $ p$ be a point in $ M$ and let $ S$ be a two-dimensional subspace of $ T_pM$. Then the sectional curvature of $ S$ at $ p$ is defined as

$\displaystyle K(S)=\frac{g(R(x,y)x,y)}{g(x,x)g(y,y)-g(x,y)^2}$
where $ x,y$ span $ S$, $ g$ is the metric tensor and $ R$ is the Riemann's curvature tensor.

This is a natural generalization of the classical Gaussian curvature for surfaces.



"sectional curvature" is owned by juanman.
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See Also: Riemannian manifold

Keywords:  curvature

Attachments:
sectional curvature determines Riemann curvature tensor (Theorem) by kerwinhui
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Cross-references: surfaces, Gaussian curvature, Riemann's curvature tensor, metric tensor, span, subspace, point, Riemannian manifold
There are 4 references to this entry.

This is version 2 of sectional curvature, born on 2006-05-08, modified 2006-09-07.
Object id is 7907, canonical name is SectionalCurvature.
Accessed 1930 times total.

Classification:
AMS MSC53B20 (Differential geometry :: Local differential geometry :: Local Riemannian geometry)
 53B21 (Differential geometry :: Local differential geometry :: Methods of Riemannian geometry)

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