Large Deviations in the Superstable Weakly Imperfect Bose Gas
Abstract
The superstable Weakly Imperfect Bose Gas {(WIBG)} was originally derived to solve the inconsistency of the Bogoliubov theory of superfluidity. Its grand-canonical thermodynamics was recently solved but not at {point of} the {(first order)} phase transition. This paper proposes to close this gap by using the large deviations formalism and in particular the analysis of the Kac distribution function. It turns out that, as a function of the chemical potential, the discontinuity of the Bose condensate density at the phase transition {point} disappears as a function of the particle density. Indeed, the Bose condensate continuously starts at the first critical particle density and progressively grows but the free-energy per particle stays constant until the second critical density is reached. At higher particle densities, the Bose condensate density as well as the free-energy per particle both increase {monotonously}.
Cite
@article{arxiv.0709.3401,
title = {Large Deviations in the Superstable Weakly Imperfect Bose Gas},
author = {J. -B. Bru and V. A. Zagrebnov},
journal= {arXiv preprint arXiv:0709.3401},
year = {2009}
}