The effect of power-law aging on a contact process is studied by simulation and using a mean-field approach. The introduced type of aging accounts for, e.g., the growth of the virus fitness (HIV infection). We find that the system may approach its stationary state in a nontrivial, nonmonotonous way. For the particular value of the aging exponent $\alpha =1\mathrm{}$ 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 $0<\mathrm{}\alpha <1,$ the absorbing-state phase transition is in the universality class of directed percolation.

• Received 21 December 2000

DOI:https://doi.org/10.1103/PhysRevE.63.046107