The Two-Loop Four-Graviton Scattering Amplitudes

Understand

We present the analytic form of the two-loop four-graviton scattering amplitudes in Einstein gravity.

• To remove ultraviolet divergences we include counterterms quadratic and cubic in the Riemann curvature tensor.
• The two-loop numerical unitarity approach is used to deal with the challenging momentum dependence of the interactions.
• We exploit the algebraic properties of the integrand of the amplitude in order to map it to a minimal basis of Feynman integrals.