title: Universal renormalization of saddle-point integrals for condensed Bose gases.
abstract: When treating the ground-state contribution exactly, a variant of the saddle-point method emerges that works even for condensed Bose gases. Results thus obtained, such as canonical partition functions, differ by universal renormalization factors from those provided by the conventional but incorrect scheme. The amended method yields the statistical properties of ideal and very weakly interacting Bose gases with a fixed number of particles with particular simplicity.
authors.affiliation: Fachbereich Physik der Philipps-Universität, Renthof 6, D-35032 Marburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Holthaus
authors.forename: E
authors.initials: E
authors.lastname: Kalinowski