Exact long-time evolution of spinless fermion systems from a highly correlated state*

We investigate the dynamics of a one-dimensional system of spinless fermions, which is initially prepared in a highly correlated groundstate of an interacting Hamiltonian. In particular, for a global quench that turns off the interaction, we evolve the initial state obtained via density matrix renormalisation group (DMRG) using analytical solutions of the equations of motion. This allows us to reach arbitrary times. We examine features of the dynamics of density-density correlations and susceptibilities on several time scales. Shortly after the quench, we identify, in addition to the typical lightcone-behavior, periodic recurrences of the initial correlations outside the lightcone. At very long times, we use our approach to investigate the Fluctuation-Dissipation theorem in this strong nonequilibrium situation.