A NUMERICAL-SIMULATION OF PRE-BIG BANG COSMOLOGY

We analyse numerically the onset of pre-big bang inflation in an inhom ogeneous, spherically symmetric Universe. Adding a small dilatonic per turbation to a trivial (Milne) background, we find that suitable regio ns of space undergo dilaton-driven inflation and quickly become spatia lly at (Omega --> 1). Numerical calculations are pushed close enough t o the big bang singularity to allow cross checks against previously pr oposed analytic asymptotic solutions.