EFFECT OF PARTICLE-PRODUCTION IN ROBERTSON-WALKER SPACETIME

We show that the Dirac equation in Robertson-Walker (RW) spacetime can be written in a two-dimensional equivalent form that parallels the mo tion of an electron in a time-varying electric field. Using the effect of particle production, a RW spacetime that describes a universe whic h contracts and re-expands almost symmetrically and becomes asymptotic ally static is simulated. The back-reaction problem is considered only through the quantum behaviour of particle production without any refe rence to Einstein field equations.