  The behaviour of solutions to the Einstein equations with a causal viscous
fluid source is investigated. In this model we consider a spatially flat
Robertson-Walker metric, the bulk viscosity coefficient is related to the
energy density as $\zeta = \alpha \rho^{m}$, and the relaxation time is given
by $\zeta/\rho$. In the case $m = 1/2$ we find the exact solutions and we
verify whether they satisfy the energy conditions. Besides, we study
analytically the asymptotic stability of several families of solutions for
arbitrary $m$. We find that the qualitative asymptotic behaviour in the far
future is not altered by relaxation processes, but they change the behaviour in
the past, introducing singular instead of deflationary evolutions or making the
Universe bounce due to the violation of the energy conditions.

General Relativity and Quantum Cosmology