Gravitation and High Energy Physics

In recent years there are growing connections between the two theories at the foundation of theoretical physics: Einstein's theory of gravitation and the standard model of particle physics formulated in terms of quantum field theory. We propose to bring together three leading researchers (2 from Berlin, 1 from Jerusalem) working on different aspects of this bridge in order to solve major issues that puzzled Einstein and researchers ever since and in order to attack and contribute fresh insight to one of the hottest modern topics in the field. The relation with Einstein's legacy and the Berlin-Jerusalem connection make it hard to imagine a topic more fitting to the name of the funding agency, the Einstein foundation in Berlin. Concretely, we shall work on two subjects. The first topic concerns modern methods of field theory, integrability, and the calculation of scattering amplitudes. This field is full of puzzles and exciting ideas including still incomplete ones. Usually these ideas are discussed in the framework of quantum field theory. However, many of them apply already at tree level and are therefore classical. They include spinors, unitarity cuts and on-shell methods, color-kinematics duality, gravity as gauge squared, and inspiration from AdS/CFT. We propose to gain further insights by applying our unique combination of perspectives, by including a purely classical understanding of these issues, and by stressing the connections with gravity. The second topic is the effective field theory (EFT) approach to Einstein's gravity (GR), in which one applies deep field theoretic tools to GR. This was already applied successfully to the issue of the post-Newtonian limit, which occupied Einstein considerably. In particular we propose to formulate a theory of the gravitational radiation and self-force, to address the extreme mass ratio inspiral, to formulate a novel theory of spinning bodies, and, finally, to obtain the field theory dual to the extreme Kerr black hole. To strengthen our collaboration we intend to organise a binational workshop (including our students and post-docs) to discuss topics of mutual interest.