The full linear causal Israel–Stewart–Hiscock theory of bulk
viscous processes in relativistic cosmological fluids is reformulated as an
effective phenomenological theory for describing particle production processes
in the early universe. Explicit expressions for the particle balance law and
particle production rates are obtained that relate the particle creation rate
to the bulk viscous (creation) pressure. The general formalism is applied to
the case of a full causal cosmological fluid with bulk viscosity coecient
proportional to the Hubble function. In this case the general solution of the
gravitational field equations can be expressed in an exact parametric form.
For an appropriate choice of the physical parameters, the dynamics of the
universe can be modelled as starting from a vacuum quasi-Minkowskian geometry,
followed by an inflationary period but ending in a non-inflationary phase. The
influence of the matter creation processes on the evolution of the universe
and the behaviour of the energy density, temperature and entropy are
investigated.