The interacting Bose gas is a system in quantum statistical mechanics where complex collective behavior emerges from the underlying many-body theory, posing crucial challenges to its rigorous mathematical description.

While for certain models of the Bose gas, known as scaling limits, precise results on the ground state energy and the low-lying spectrum of excitations have been obtained, much less is known in the thermodynamic limit. In this talk I will discuss the Bose gas in a box with Neumann boundary conditions and show how it allows us to obtain lower bounds for the ground state energy in the thermodynamic limit. I will also discuss extensions to positive temperature. (Joint works with Robert Seiringer, Andreas Deuchert and David Stocker.)

Zoom talk (https://us02web.zoom.us/j/4901115910)