Gauge conditions in interaction theory
Haorong Wu
Suppose we choose the Lorenz gauge conditions for an EM field, ##\partial_\mu A^\mu=0##. The EOMs for the field are given by ##\Box A^\mu=J^\mu##, with ##\partial_\mu J^\mu=0##. If the interaction time is ranged from ##-\infty## to ##t##, ##A^\mu## satisfy the Lorenz gauge, because ##A^\mu(x) =... Read more