Full causal bulk-viscous cosmological models

Abstract

New exact solutions of the gravitational field equations for a homogeneous flat Friedmann-Robertson-Walker Universe filled with a causal bulk-viscous fluid with a bulk viscosity coefficient proportional to the Hubble function are obtained in the framework of the full causal Israel-Stewart-Hiscock (ISH) theory. The evolution equation of the Universe is reduced to a first kind Abel-type first-order differential equation and new classes of exact solutions of the field equations are generated from some particular solutions of this equation leading to two classes of general solutions of the Einstein field equations corresponding to particular values of the parameters entering in the physical model. The obtained solutions are represented mathematically in an exact parametric form and are interpreted physically as describing cosmological particle production. The evolution of the temperature, entropy, deceleration parameter, and bulk viscosity coefficient is also considered for each model. © 1998 American Institute of Physics.