MATTER PRODUCTION IN THE EARLY UNIVERSE

The coupled Dirac-Einstein equations with a negative cosmological cons tant for an open FRW universe are studied in detail. The corresponding solutions admit bounces (hooked right arrow minimal radius) of the un iverse such that the matter energy in any comoving 3-volume is either increased or decreased during the bounce according to whether the boun ce pressure of the spinor field is appropriately negative or not. If m atter is generated (annihilated) during a bounce, the universe subsequ ently becomes larger (smaller) than before the bounce. Therefore matte r can be generated only during the growth of the universe, but it is a nnihilated again during the subsequent shrinking phase, which together with the growing phase forms a cosmic supercycle.