Theory HEP Seminar

The MHV-vertex Expansion for Gravity Amplitudes

Sayeh Rajabi

Perimeter Institute

It has been a longstanding problem to determine the Cachazo-Svrcek-Witten (or MHV-vertex) expansion of gravity amplitudes for any number of external gravitons. The known systematic approach towards this goal, proposed by Risager, breaks down starting at 12-graviton amplitude. Recently the complete tree-level S-matrix of N = 8 supergravity in all R-charge sectors was proposed by Cachazo and Skinner. We used this new formula in the Grassmannian representation to obtain the MHV-vertex expansion of gravity. In this talk, I will review the recent progresses in the scattering amplitude of gravity and present our new results on gravity's MHV expansion.