Curvature invariant

In Riemannian geometry and pseudo-Riemannian geometry, curvature invariants are scalar quantities constructed from tensors that describe the curvature of a space or spacetime. Because they are scalars, their values do not depend on the coordinate system used, making them useful for comparing the intrinsic curvature of different geometries. These tensors are usually the Riemann tensor, the Weyl tensor, the Ricci tensor and tensors formed from these by the operations of taking dual contractions and covariant differentiations.