Quantum field theory, Lecture 13

This winter semester (2016-2017) I am giving a course on quantum field theory. This course is intended for theorists with familiarity with advanced quantum mechanics and statistical physics. The main objective is introduce the building blocks of quantum electrodynamics. Here in Lecture 13 we continue the discussion of the Feynman diagram expansion for scattering amplitudes and also spend some more time discussing the operational meaning of divergences and cutoffs.