Retarded potential

The retarded potential ( German: delayed potential) is the name given to the mathematical form of the potential in the electromagnetic field theory and other field theories, in which changes of the field at a finite speed (speed of light ) and not instantaneous (immediately, instantaneously ) spread. Occurs in the analysis of time-dependent problems such as emission of electromagnetic waves. In the field of electrostatics and magnetostatics and the Newtonian theory of gravitation, however, time dependencies are neglected.

Mathematically, the potential of the solution of ( following from the Maxwell equations) inhomogeneous wave equation in three space dimensions

Where on the right side is a source term. The solution

Called retarded potential. It depends on the place at the time only of the inhomogeneity on the backward light cone of from. The inhomogeneity affects the solution of time ( hence the name) with the speed of light.

The solution

Ie in accordance with avanciertes potential. This describes, for example, a sink, which absorbs an existing field. With retarded and thus can be described avanciertem potential emission and absorption of fields.