Quasi-classical dynamics of quantum particles interacting with radiation

We study the effective dynamics of microscopic models of quantum particles interacting with a bosonic radiation in the quasi-classical limit. In the regime considered, the field has high intensity and can be described as a macroscopic object and suitably approximated by its classical counterpart, while the particles retain their quantum nature. We prove that the field evolves freely, playing the role of a classical environment, while the particles dynamics is generated by an effective Schroedinger operator and averaged over the possible configurations of the field.