On a Generalization of Curvature Homogeneous Spaces

Abstrakt

Sekigawa proved in 1977 that a 3-dimensional Riemannian manifold which is curvature homogeneous up to order 1 in the sense of I.M. Singer is always locally homogeneous.

We deal here with the modification of the curvature homogeneity which is said to be "of type (1, 3)". We give example of a 3-dimensional Riemannian manifold which is curvature homogeneous up to order 1 in the modified sense but still not locally homogeneous.

Klíčová slova

• Riemannian manifold
• curvature homogeneous manifold
• locally homogeneous space