Excitation Spectrum for Bose Gases beyond the Gross-Pitaevskii Regime

Christian Brennecke, Marco Caporaletti, Benjamin Schlein

We consider Bose gases of $N$ particles in a box of volume one, interacting through a repulsive potential with scattering length of order $N^{1-\kappa }$, for $\kappa >0$. Such regimes interp…