Application No. 681/15 PI Name: Barak Kol Scientific abstract – Scattering amplitudes; High energy gravity

In recent years it was realized that perturbative gauge theory (and gravity) is far from being well-understood. A myriad of new concepts and tools were found to improve over the standard perturbation theory a la Feynman and often to reduce computation dramatically. However, it is not clear yet how these different concepts fit together optimally. Just like the Lagrangian underlies the standard Feynman rules, some believe that the new concepts hint at an alternative, deep formulation of gauge theory. These issues are the basis for the field known as “scattering amplitudes”. Clearly, these issues lie at the heart of Quantum Field Theory. They are important not only theoretically but also experimentally as these methods already enabled to compute valuable cross-sections for accelerators including the LHC. The main focus of this proposal is to be the first Israeli group to enter scattering amplitudes, in parallel with A. Sever who recently arrived, to study and review the literature and seek to contribute to the ongoing worldwide effort to address the above-mentioned issues by applying our gravitational, geometrical and physical skills. The proposed research group started working in the field in fall 2013 and was already able t