In general relativity, the peeling theorem describes the asymptotic behavior of the Weyl tensor as one goes to null infinity. Let be a null geodesic in a spacetime from a point p to null infinity, with affine parameter . Then the theorem states that, as tends to infinity:
where is the Weyl tensor, and we used the abstract index notation. Moreover, in the Petrov classification, is type IV, is type III, is type II (or II-II) and is type I.