We discuss the role of the initial conditions for the dynamical anomalies observed in the quasi-stationary states of the Hamiltonian mean field (HMF) model.

We study the dynamics of a Hamiltonian system of N classical spins with infinite-range interaction. We present numerical results which confirm the existence of metaequilibrium quasi stationary states (QSS), characterized by non-Gaussian velocity distributions, anomalous diffusion, Lévy walks...