出典:Wikipedia
出典:『Wikipedia』 (2011/05/27 14:30 UTC 版)
In differential geometry, the Cotton tensor on a (pseudo)-Riemannian manifold of dimension n is a third-order tensor conomitant of the metric, like the Weyl tensor. Just as the vanishing of the Weyl tensor for n ≥ 4 is a necessary and sufficient condition for the manifold to be conformally flat, the same is true for the Cotton tensor for n = 3, while for n < 3 it is identically zero.