Covariant techniques in Quantum Field Theory
arXiv:2203.11292
Abstract
In this paper some techniques useful to perform quantum field theory computations in a covariant manner are reviewed. In particular the background field gauge, the zeta function regularization and the heat kernel approach are highlighted. Some detailed calculations of the Schwinger-de Witt coefficients of the small proper time expansion of the heat kernel are also repeated in detail. This work reports lectures given by Enrique Álvarez at the IFT-UAM-CSIC in Madrid.
96 pages, LaTeX, lecture notes given by Enrique Álvarez at the IFT-UAM-CSIC in Madrid. New section added. References added. Typos corrected