Lectures of Quantum Field Theory (repost)

The introduction of quantum field theory methods has led to a kind of “revolution” in condensed matter theory. This resulted in the increased importance of Feynman diagrams or diagram technique.

With the discovery of the Higgs boson, the LHC experiments have closed the most important gap in our understanding of fundamental interactions, confirming that such interactions between elementary particles can be described by quantum field theory, more specifically by a renormalizable gauge theory. This theory is a priori valid for arbitrarily high energy scales and does not require an ultraviolet completion.