A Lower Bound on the Critical Momentum of an Impurity in a BoseEinstein Condensate
Abstract
In the BogoliubovFröhlich model, we prove that an impurity immersed in a BoseEinstein condensate forms a stable quasiparticle when the total momentum is less than its mass times the speed of sound. The system thus exhibits superfluid behavior, as this quasiparticle does not experience friction. We do not assume any infrared or ultraviolet regularization of the model, which contains massless excitations and pointlike interactions.
 Publication:

arXiv eprints
 Pub Date:
 November 2023
 DOI:
 10.48550/arXiv.2311.05361
 arXiv:
 arXiv:2311.05361
 Bibcode:
 2023arXiv231105361H
 Keywords:

 Mathematical Physics;
 Mathematics  Spectral Theory;
 Quantum Physics;
 Primary 81V73;
 Secondary 81Q10;
 47A10
 EPrint:
 10 pages