Umberto Morellini (Pisa)

Norm Approximation of Bosons Mean-Field Dynamics by Quasi-free Evolution.

In this talk, I will consider the quantum many-body evolution of a homogeneous Bose gas in three dimensions in the mean-field scaling regime. I will study a class of initial data describing finitely many excitations over a quasi-stationary Bose-Einstein condensate. Using a rigorous version of Bogolyubov’s theory, I will prove that the many-body evolution can be approximated in Fock space norm by a quasi-free bosonic evolution of the excitations with an error which grows linearly in time. This talk is based on an ongoing work with Niels Benedikter (University of Milan) and Chiara Boccato (University of Pisa).