%0 Journal Article
%T Exact 1/N and Optimized Perturbative Evaluation of mu_c for Homogeneous Interacting Bose Gases
%+ Laboratoire de Physique Mathématique et Théorique (PMT)
%+ Departamento Física [Florianópolis]
%A Kneur, Jean-Loïc
%A Pinto, Marcus
%Z 12 pages, 2 figures. We have performed a refined and extended numerical analysis to take into account the very recent results of Ref. [15]
%< avec comité de lecture
%Z 04-057
%@ 1050-2947
%J Physical Review A : Atomic, molecular, and optical physics [1990-2015]
%I American Physical Society
%V 71
%P 033613
%8 2005
%D 2005
%Z cond-mat/0408538
%R 10.1103/PhysRevA.71.033613
%K Static properties of Bose-Einstein condensates
%K thermodynamical
%K statistical
%K and structural properties
%K Boson systems (quantum statistical mechanics)
%K Finite-temperature field theory
%K Summation of perturbation theory in QCD
%Z PACS: 03.75.Hh, 05.30.Jp, 11.10.Wx, 12.38.Cy
%Z Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
%Z Physics [physics]/High Energy Physics - Theory [hep-th]Journal articles
%X In the framework of the O(N) three-dimensional effective scalar field model for homogeneous dilute weakly interacting Bose gases we use the 1/N expansion to evaluate, within the large N limit, the parameter r_c which is directly related to the critical chemical potential mu_c. This quantity enters the order-a^2 n^{2/3} coefficient contributing to the critical temperature shift Delta T_c where a represents the s-wave scattering length and n represents the density. Compared to the recent precise numerical lattice simulation results, our calculation suggests that the large N approximation performs rather well even for the physical case N=2. We then calculate the same quantity but using different forms of the optimized perturbative (variational) method, showing that these produce excellent results both for the finite N and large-N cases.
%G English
%L hal-00259668
%U https://hal.science/hal-00259668
%~ CNRS
%~ UNIV-MONTP2
%~ UNIV-MONTPELLIER
%~ UM1-UM2