Constructing Gravity Amplitudes from Real Soft and Collinear Factorisation

Understand

Soft and collinear factorisations can be used to construct expressions for amplitudes in theories of gravity.

• We generalise the "half-soft" functions used previously to "soft-lifting" functions and use these to generate tree and one-loop amplitudes.
• In particular we construct expressions for MHV tree amplitudes and the rational terms in one-loop amplitudes in the specific context of N=4 supergravity.
• To completely determine the rational terms collinear factorisation must also be used.