Gravity from rational curves in twistor space
Freddy Cachazo and David Skinner
Accepted
This paper presents a new formula which is conjectured to yield all tree amplitudes in \cN = 8 supergravity. The amplitudes are described in terms of higher degree rational maps to twistor space. The resulting expression has manifest \cN = 8 supersymmetry and is manifestly permutation symmetric in all external states. It depends monomially on the infinity twistor that explicitly breaks conformal symmetry to Poincaré. We have carried out various non-trivial analytic and numerical checks of the formula, for up to eight external states with arbitrary helicities.