Pure radiation in space-time models that admit integration of the eikonal equation by the separation of variables method

Abstract

We consider space-time models with pure radiation, which admit integration of the eikonal equation by the method of separation of variables. For all types of these models, the equations of the energy-momentum conservation law were integrated. The resulting form of metric, energy density and wave vectors of radiation as functions of metric for all types of spaces under consideration is presented. The solutions obtained can be used for any metric theories of gravitation.