Kinetic and chemical equilibrium of the Universe and gravitino
  production
  Flat directions in generic supersymmetric theories can change the thermal
history of the Universe. A novel scenario was proposed earlier where the vacuum
expectation value of the flat directions induces large masses for all the gauge
bosons and gauginos. This delays the thermalization of the Universe after
inflation and solves the gravitino problem. In this article we perform a
detailed calculation of the above scenario. We include the appropriate initial
state particle distribution functions, consider the conditions for the
feasibility of the non-thermal scenario, and investigate phase space
suppression of gravitino production in the context of heavy gauge bosons and
gauginos in the final state. We find that the total gravitino abundance
generated is consistent with cosmological constraints.
