Bulk-viscosity-driven inflationary model

Abstract

Bulk viscosity associated with the production of heavy particles during the grand-unified-theory phase transition can lead to exponential or ``generalized'' inflation. The condition of inflation proposed is independent of the details of the phase transition and remains unaltered in the presence of a cosmological constant. Such a mechanism avoids the extreme supercooling and reheating needed in the usual inflationary models. The standard baryogenesis mechanism can be maintained.