  The effect of power-law aging on a contact process is studied by simulation
and using a mean-field approach. We find that the system may approach its
stationary state in a nontrivial, nonmonotonous way. For the particular value
of the aging exponent, $\alpha=1$, we observe a rich set of behaviors:
depending on the process parameters, the relaxation to the stationary state
proceeds as $1/\ln t$ or via a power law with a nonuniversal exponent.
Simulation results suggest that for $0<\alpha<1$, the absorbing-state phase
transition is in the universality class of directed percolation.
