The **Sasaki metric** is a natural choice of Riemannian metric on the tangent bundle of a Riemannian manifold.
Introduced by Shigeo Sasaki in 1958.

## Construction

Let be a Riemannian manifold, denote by the tangent bundle over . The Sasaki metric on is uniquely defined by the following properties:

- The map is a Riemannian submersion.
- The metric on each tangent space is the Euclidean metric induced by .
- Assume is a curve in and is a parallel vector field along . Note that forms a curve in . For the Sasaki metric, we have for any ; that is, the curve normally crosses the tangent spaces .

## References

- S. Sasaki, On the differential geometry of tangent bundle of Riemannian manifolds, Tôhoku Math. J.,10 (1958), 338–354.

This page was last edited on 8 February 2024, at 04:35