We consider systems of N bosons trapped on the two-dimensional unit torus, in the Gross-Pitaevskii regime, where the scattering length of the repulsive interaction is exponentially small in the number of particles. We show that low-energy states exhibit complete Bose-Einstein condensation, with almost optimal bounds on the number of orthogonal excitations.
Keywords: Bose–Einstein condensation; Gross-Pitaevskii regime; Interacting bosons; Two dimensional Bose gas.
© The Author(s) 2021.