## Thermal Properties of Interacting Bose Fields and Imaginary-Time Stochastic Differential Equations

• Abstract: Matsubara Green's functions for interacting bosons are expressed as classical statistical averages corresponding to a linear imaginary-time stochastic differential equation. This makes direct numerical simulations applicable to the study of equilibrium quantum properties of bosons in the non-perturbative regime. To verify our results we discuss an oscillator with quartic anharmonicity as a prototype model for an interacting Bose gas. An analytic expression for the characteristic function in a thermal state is derived and a Higgs-type phase transition discussed, which occurs when the oscillator frequency becomes negative.

### Additional Services

Author: L. I. Plimak, M. Fleischhauer, D. F. Walls urn:nbn:de:hbz:386-kluedo-12141 Preprint English 1998 1998 Technische Universität Kaiserslautern 2001/07/02 Fachbereich Physik 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik Standard gemäß KLUEDO-Leitlinien vor dem 27.05.2011

$Rev: 13581$