Abstract. Among others, Uhling and Uhlenbeck, Kaniadakis and Quarati and Kadanoff have suggested to describe the evolution of quantum systems exhibiting Fermi–Dirac and Bose–Einstein statistics by means of classical but nonlinear evolution equations for density measures such as generalized Boltzmann equations and nonlinear Fokker–Planck equations. We use this approach in order to derive classical Langevin equations for quantum systems and apply the Langevin equations thus obtained to two fundamental quantum systems, namely, the free electron gas and blackbody radiation.

PACS numbers: 05.40.−a, 71.10.Ca

Print publication: Issue 11 (19 March 2004)
Received 30 January 2004
Published 2 March 2004