Bogoliubov spectrum of interacting Bose gases

Abstract

We study the large-N limit of a system of N bosons interacting with a potential of intensity 1/N. When the ground state energy is to the first order given by Hartree's theory, we study the next order, predicted by Bogoliubov's theory. We show the convergence of the lower eigenvalues and eigenfunctions towards that of the Bogoliubov Hamiltonian (up to a convenient unitary transform). We also prove the convergence of the free energy when the system is sufficiently trapped. Our results are valid in an abstract setting, our main assumptions being that the Hartree ground state is unique and non-degenerate, and that there is complete Bose-Einstein condensation on this state. Using our method we then treat two applications: atoms with ''bosonic'' electrons on one hand, and trapped 2D and 3D Coulomb gases on the other hand.

Final version to appear in Comm. Pure Appl. Math. Communications on Pure and Applied Mathematics (2013) in press

References in corpus (5)

• The Second Order Upper Bound for the Ground Energy of a Bose Gas
• Geometric methods for nonlinear many-body quantum systems
• The ground state energy of a low density Bose gas: a second order upper bound
• The ground state energy of the weakly interacting Bose gas at high density
• A Nonlinear Model for Relativistic Electrons at Positive Temperature

Cited by in corpus (1)

• Bose particles in a box II. A convergent expansion of the ground state of the Bogoliubov Hamiltonian in the mean field limiting regime