KLEIN-ALFVEN MODELS IN GENERAL-RELATIVITY

We consider two simplified models of matter-antimatter universes in th e general relativity. In model I, an equation of state is chosen to re present pure radiation at high densities and dust at low ones. In mode l II, periodic dust-radiation oscillations are prescribed externally. Analytical relations between density and cosmic time are obtained for both cases, and the scale factor as a function of time is found numeri cally for model II. Both models are qualitatively similar to standard relativistic ones and, as expected, have initial singularities.