Classical Physics from an On-Shell Perspective

How does classical physics emerge from the quantum world?  In this talk, I’ll introduce the KMOC (Kosower, Maybee, and O’Connell ) formalism, which makes this connection precise by showing how classical dynamics can be derived directly from quantum scattering amplitudes. This on-shell viewpoint offers a simple and transparent way to understand how quantum interactions give rise to familiar classical behaviour, from forces to radiation. I’ll explain the main ideas behind the formalism and how it connects quantum field theory to the classical world.