Comment on "Fluctuation-dissipation relations in the nonequilibrium critical dynamics of Ising models".
Recently Phys. Rev. E 68, 016116 (2003)]] proposed an alternative way to compute numerically the fluctuation-dissipation ratios in nonequilibrium critical systems. Using well-known facts of nonequilibrium critical dynamics I show that the leading contributions of the quantities they consider are in fact one-time quantities which are independent of the waiting time. The ratio of these one-time quantities determines the slope of the straight lines observed in the fluctuation-dissipation plots of Mayer et al.
Institut für Theoretische Physik I, Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany.
Michel
M
Pleimling