We investigate the influence of correlated initial conditions on the temporal evolution of a (d+1)-dimensional critical directed percolation process. Generating initial states with correlations <s_i*s_{ i+r}>~r^(sigma-d) we observe that the density of active sites in Monte-Carlo simulations evolves as rho(t)~t^kappa. The exponent kappa depends continuously on sigma and varies in the range -beta/nu_{ ||}<=kappa<=eta. Our numerical results are confirmed by an exact field-theoretical renormalization group calculation.
Categories: cond-mat.stat-mech