Lorenz gauge condition

Summary

The Lorenz gauge condition is the requirement that the four-divergence of the electromagnetic four-potential vanish. It is a gauge fixing condition that is the same in every inertial frame. In this gauge each component of the potential solves an inhomogeneous wave equation, with the charge density or a current component as source. It is named after Ludvig Lorenz, and it is often misattributed to Hendrik Lorentz.