arXiv:2205.12218 · Annales Henri Poincaré
The Excitation Spectrum of Two-Dimensional Bose Gases in the Gross–Pitaevskii Regime
Cristina Caraci, Serena Cenatiempo, Benjamin Schlein
Abstract
Abstract We consider a system of N bosons, in the two-dimensional unit torus. We assume particles to interact through a repulsive two-body potential, with a scattering length that is exponentially small in N (Gross–Pitaevskii regime). In this setting, we establish the validity of the predictions of Bogoliubov theory, determining the ground state energy of the Hamilton operator and its low-energy excitation spectrum, up to errors that vanish in the limit $$N \rightarrow \infty $$ N → ∞ .