Exact model of gravitational wave and pure radiation

An exact non-perturbative model of a gravitational wave with pure radiation is constructed. It is shown that the presence of dust matter in this model contradicts Einstein’s field equations. Exact solution of Einstein equations for gravitational wave and pure radiation is obtained. The trajectories of propagation and characteristics of radiation are found. For the considered exact model of a gravitational wave, a retardet time equation for radiation is obtained. The obtained results are used to construct an exact model of gravitational wave and pure radiation for Bianchi type IV universe.