Scattering Amplitudes and Beyond

Coordinators: Henriette Elvang, Radu Roiban, David Skinner, and Jaroslav Trnka

Scientific Advisors: Nima Arkani-Hamed, Zvi Bern, Alexander Goncharov, and Juan Maldacena

The study of quantum scattering amplitudes has played a fundamental role in the development of theoretical physics. Feynman diagrams, the traditional method to compute them, are inefficient when describing amplitudes with many external particles, or at high loop order, and this is particularly the case in Yang-Mills theory and Gravity. Therefore, over the past several years, many alternative approaches have been developed.

Far from being a mere technical toolbox, these new ideas are currently revolutionizing both our understanding of and ability to actually compute scattering amplitudes. They shed remarkable new light on powerful new mathematical structures present at the heart of quantum field theory and string theory, and offer the promise of new descriptions of Nature in which sacred properties of quantum field theory -- unitarity, analyticity and even the very notion of spacetime -- become emergent concepts.

The new approaches involve a wealth of ideas drawn from both physics and mathematics, for example linking amplitudes to geometry. The purpose of this KITP program is to bring together experts in quantum field theory, string theory, and twistor theory with experts in algebraic geometry, number theory and combinatorics to further establish communication between the fields and to advance progress on understanding scattering amplitudes.