Co-authors: Lionel Mason (University of Oxford), Ricardo Monteiro (CERN), Piotr Tourkine (University of Cambridge)

Worldsheet formulations of quantum field theories have had wide-ranging impact on the study of scattering amplitudes. However, the mathematical framework becomes very challenging on the higher-genus worldsheets required to describe loop effects. I will describe how, in such worldsheet models based on the scattering equations, formulae on higher-genus surfaces can be transformed to ones on the Riemann sphere. My talk will focus on new developments at two loops for both supergravity and super Yang-Mills theory, and briefly discuss a proposal for the all-loop integrand.

Related Links ◾http://arxiv.org/abs/1507.00321
◾http://arxiv.org/abs/1511.06315