Fox and Hedgehog Seminar Series - 'Understanding scattering using periodic boundary conditions'

Scattering amplitudes are an important observable in quantum field theory. However, in certain quantum field theories (such as quantum chromodynamics or QCD) it can be very challenging to reliably predict scattering amplitudes of low-energy bound states. In this talk, I will explain how progress has been made by deriving mathematical relations between amplitudes and the discrete energies of the system confined to a finite, periodic volume. This is useful, in part because methods exist to calculate those energies numerically. But I will also argue that deriving these finite-volume relations has taught us a great deal about scattering in general.