Doppler Signature in Electrodynamic Retarded Potentials

Abstract

The presence of the term $\left(\case{v}{c}\right)$ that characterizes the electrodynamic retarded potentials, also known as Li\'enard-Wiechert potentials, is thought to be reminiscent of a Doppler effect. Here, we show that these potentials are consistent with the Doppler shifted electromagnetic (e.m.) field generated by a charge moving along a generic trajectory with respect to the laboratory reference frame. Of course, the retarded potentials derived here are formally the same as those reported in the current literature. Nonetheless, this work sheds a new light on the origin of the electrodynamics retarded fields, while offering a direct physical interpretation of the term $\left(\case{v}{c}\right)$ characterizing the related potentials.