# The Bogolubov variational model and its accuracy as an approximation to many-body Bose systems

Jan Philip Solovej (Copenhagen)
Mathematics Seminar
Tuesday, 5 May, 2020 | 16:00– | Zoom

I will discuss the Bogolubov variational model that arises when a many-body bosonic Hamiltionian is restricted to quasi-free states. For simplicity I will restrict attention to ground states. By definition the variational model gives an upper bound on the many-body ground state energy. I will discuss examples where it is, in fact, a good approximation, such as the Lieb-Liniger model, the one- and two-component charged Bose gases and the dilute Bose gas in three dimensions.