Quasi-positively Ricci-curved Riemannian manifold: Difference between revisions

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===Symbol-free definition===
===Symbol-free definition===


A [[Riemannian manifold]] <math>M</math> is said to have '''quasi-positive Ricci curvature''' if it satisfies the following two conditions:
A [[Riemannian manifold]] <math>M</math> is said to have '''quasi-positive Ricci curvature''' or to be '''quasi-positively Ricci-curved''' if it satisfies the following two conditions:


* The Ricci curvature is everywhere nonnnegative
* The Ricci curvature is everywhere nonnnegative
* There is a point on the manifold at which the Ricci curvature is strictly positive in all directions
* There is a point on the manifold at which the Ricci curvature is strictly positive in all directions
==References==
* ''On the structure of complete manifolds on nonnegative Ricci curvature'' by Jeff Cheeger and Detlef Gromoll


==Relation with other properties==
==Relation with other properties==

Revision as of 11:45, 7 July 2007

This article defines a property that makes sense for a Riemannian metric over a differential manifold

Definition

Symbol-free definition

A Riemannian manifold is said to have quasi-positive Ricci curvature or to be quasi-positively Ricci-curved if it satisfies the following two conditions:

  • The Ricci curvature is everywhere nonnnegative
  • There is a point on the manifold at which the Ricci curvature is strictly positive in all directions

References

  • On the structure of complete manifolds on nonnegative Ricci curvature by Jeff Cheeger and Detlef Gromoll

Relation with other properties

Stronger properties