Quantum field theory, Lecture 11

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 11 we continue the discussion of the Feynman rules for phi4 theory in position and momentum space, prove that vacuum bubbles cancel, and discuss a little renormalisation theory.