Gauge fixing is a procedure used in theoretical physics, particularly in the context of gauge theories, to eliminate the redundancy caused by gauge symmetries. Gauge symmetries are transformations that can be applied to the fields in a theory without changing the physical content of the theory. Because of these symmetries, multiple field configurations can describe the same physical situation, leading to an overcounting of degrees of freedom.
Articles by others on the same topic
Gauge fixing removes the degeneracy among gauge-equivalent field configurations so that the kinetic operator has an inverse propagator.