Dynamical properties of correlated many-body systems from Quantum Monte Carlo simulations

I will discuss recent advances in the ab-initio study of correlated many-body quantum systems, and in particular the possibility to compute dynamical correlation functions from first principles using Quantum Monte Carlo techniques. Using the Hubbard model as an example, I will address the calculation of the spectral function, that can be experimentally measured in spectroscopy experiments, and the density structure factors, that can be measured in scattering experiments. The purpose is to allow us to directly compare the predictions of Quantum Monte Carlo techniques with experiments. I will present results for cold atomic Fermi systems in the BEC-BCS crossover in two and three dimensions and for cold atoms on optical lattices. I will also discuss results and perspectives for repulsive models, in connection with high-temperature superconductivity.