On the conformal transformation between two anisotropic fluid spacetimes

We investigate the necessary conditions for two spacetimes, which are solutions to Einstein field equations with an anisotropic matter source, be related each other by means of a conformal transformation. As result, we obtain that if one such spacetimes is generalization Robertson-Walker solution vanishing acceleration and vorticity, then has in this class as well, i.e. factor will constant function on hypersurfaces orthogonal fluid flow lines. The evolution equation appears naturally direct consequence transformation Ricci tensor.