Résumé
Europhys. Lett. 46, 637 (1999) By using extensive Molecular Dynamics simulations, we have determined the violation of the fluctuation-dissipation theorem in a Lennard-Jones liquid quenched to low temperatures. For this we have calculated$X(C)$ , the ratio between a one particle time-correlation function$C$and the associated response function. Our results are best fitted by assuming that$X(C)$is a discontinuous, piecewise constant function. This is similar to what is found in spin systems with one step replica symmetry breaking. This strengthen the conjecture of a similarity between the phase space structure of structural glasses and such spin systems.