title: Critical temperature of a trapped, weakly interacting Bose gas.
abstract: We report on measurements of the critical temperature of a harmonically trapped, weakly interacting Bose gas as a function of atom number. Our results exclude ideal-gas behavior by more than two standard deviations, and agree quantitatively with mean-field theory. At our level of sensitivity, we find no additional shift due to critical fluctuations. In the course of this measurement, the onset of hydrodynamic expansion in the thermal component has been observed. Our thermometry method takes this feature into account.
authors.affiliation: Groupe d'Optique Atomique, Laboratoire Charles Fabry de l'Institut d'Optique, UMR 8501 du CNRS, 91403 Orsay CEDEX, France.
authors.forename: F
authors.initials: F
authors.lastname: Gerbier
authors.forename: J H
authors.initials: JH
authors.lastname: Thywissen
authors.forename: S
authors.initials: S
authors.lastname: Richard
authors.forename: M
authors.initials: M
authors.lastname: Hugbart
authors.forename: P
authors.initials: P
authors.lastname: Bouyer
authors.forename: A
authors.initials: A
authors.lastname: Aspect