TFY4210 Quantum field theory of many-particle systems

We have seen that a massless scalar field in two-dimensional Minkowski space gives rise to the Unruh effect seen by accelerated observers, which means that in the Minkowski vacuum,

Current density operators and linear response description of coupling a system of electrons to an external electric field.. This problem deals with the proof of some results that were

Assurne that the incoming (resp. outgoing) electron has quantum numbers p, s (resp. b ) Use the Feynman rules in the Appendix to write down the corresponding

Solution FY3464 Quantum Field Theory I, Oct... Solution FY3464 Quantum Field Theory

We have developed Feynman diagrams and Feynman rules for the impurity averaged single particle Greens function in this problem. For a given diagram, we let n be the order of the

The irreducible diagrams are marked with a tick, while the reducible diagrams are marked with a red line where an electron line can be cut to cut the diagram in two.. The

In the lectures we developed a perturbation expan- sion (in the electron-impurity scattering potential) for the impurity-averaged Matsubara single-particle Green function G(k, ip m

(Besides, it turned out to be unable to describe particles with spin.) Dirac therefore considered an equation that was first order in the time derivative (like the Schr¨