Title: "Fluctuation-dissipation relations and the computation 
       of response functions out of equilibrium"


Abstract: A unified derivation of the off-equilibrium 
fluctuation-dissipation relations (FDR) is given for Ising
and continous spins to arbitrary order in the external
perturbation, within the framework of Markovian stochastic
dynamics. Similarities and differences with other forms
of FDR in the literature are analysed and discussed.
Knowledge of the FDR allows to develop "zero field"
algorithms for the efficient numerical computation of the
response functions. The method based on our form of the FDR
is illustrated in the phase-ordering process of the Ising ferromagnet 
quenched to below the critical point and in the Edwards-Anderson 
spin glass, where a second ordere FDR is needed. 
As an additional application, the effective temperature is extracted 
at nonlinear order, in the context of coarsening systems, and is shown 
to be consistent with the one obtained from the linear FDR.