A Modern View of Scattering Amplitudes

A Modern View of Scattering Amplitudes Henriette Elvang, University of Michigan Physics Colloquium 2021-09-16 Amplitudes encode the probability of scattering processes, such as gluon scattering at the LHC. They harbor an intrinsic mathematical beauty that can be exploited to devise new calculational methods that are far more efficient than Feynman rules. Moreover, their structure also reveal new surprising properties such as the "double copy": in one form, it says that classical gravity can be formulated as a certain "doubling" of classical Yang-Mills theory (the theoretical model of gluons). This has a very clean and clear meaning at the level of scattering amplitudes and it extends to other examples too. I'll introduce the modern amplitudes program and the double-copy along with some recent results.