Abstract: Scattering phenomena are ubiquitous. Quantum field theory provides a prescription to calculate scattering amplitudes by using Feynman diagrams. However, this systematic procedure is often tedious, even for tree-level scattering. One often finds surprisingly simple answers to amplitudes that require summing over millions of Feynman diagrams. Over the past couple of decades, on-shell methods have developed that are based on factorization of amplitudes when internal momenta are set on-shell. These developments have happened largely for massless particles, with the amplitudes of N = 4 SYM being the prototype. To develop on-shell methods for amplitudes involving massive particles, the Coulomb branch of N=4 SYM is expected to be the prototype. We will discuss on-shell methods for tree and loop amplitudes in this theory. We will also discuss ideas of the positive geometry program, where one intends to build the amplitude by using the combinatorics of its singularities. Based on arXiv:2308.05705, 2311.17763.

Meeting ID: 990 1914 2403
Passcode: 371299