Abstract: Scattering amplitudes A, or equivalently the S-matrix S = 1 + iA, are mathematical quantities which encode the quantum mechanical probabilities for particle scattering processes. Amplitudes constitute an entire subfield of theoretical physics and are essential tools for experimental physics, from the Large Hadron Collider (LHC) to the Laser Interferometer Gravitational-Wave Observatory (LIGO). In this talk, I will describe my research using “bootstrap” techniques and consistency principles to study the math and physics of amplitudes themselves. This work is part of the modern S-matrix bootstrap program, a framework for exploring the landscape of consistent quantum theories, including extensions of the Standard Model and theories of quantum gravity.

I will begin the talk with a brief history of particle physics and the S-matrix bootstrap program. I will then introduce several physical principles which constrain amplitudes, namely Lorentz invariance, analyticity, unitarity, and crossing symmetry. Finally, I will sketch a recent proof using these principles to bound the allowed masses and spins of particles in any consistent quantum theory. This talk will assume very little prior knowledge of particle physics, but I will use some complex analysis and group theory with a physicist’s level of rigor.

Contact: AIM Seminar Organizers