Faddeev-Popov Gauge Fixing and the Curci-Ferrari Model

This chapter starts by presenting the standard Faddeev-Popov procedure for fixing the gauge in non-abelian gauge theories, together with its main properties and limitations. It then reviews some of the approaches that have been devised in order to go beyond it and, then, particularizes to the Curci-Ferrari model, a more phenomenological take on the question. After a discussion of the connections of the model with various other approaches, its main results are presented in regard to the known infrared properties of Landau gauge Yang-Mills theory in the vacuum. Finally, the difficulties that appear when using the model at finite temperature are discussed, serving as the main motivation for the developments in the rest of the book.