Baryogenesis in theories with large extra spatial dimensions

We describe a simple and predictive scenario for baryogenesis in theories w ith large extra dimensions which resembles Affleck-Dine baryogenesis. The A ffleck-Dine field is a complex scalar field carrying a U(1)(chi) charge whi ch is dynamically broken after the end of inflation. This generates an exce ss of chi over <(<chi>)over bar> which then decays into Standard Model ferm ions to produce an excess of baryons over antibaryons. Our model is very co nstrained because the Affleck-Dine field has to be sufficiently flat during inflation. It is also a source for density fluctuations which can be teste d in the coming satellite and balloon experiments. (C) 2001 Elsevier Scienc e B.V. All rights reserved.