Quantum-field-theoretical approach to phase-space techniques: Symmetric Wick theorem and multitime Wigner representation

摘要: In this work we present the formal background used to develop methods in earlier works extend truncated Wigner representation of quantum and atom optics order address multi-time problems. The has proven be great practical use, especially numerical study dynamics Bose condensed gases. these cases, it allows for simulation effects which are missed entirely by other approximations, such as Gross-Pitaevskii equation, but does not suffer from severe instabilities more exact methods. treatment interacting many-body systems is an extremely difficult task, ability beyond single-time situations adds another powerful technique available toolbox. This article gives mathematics behind development our "time-Wigner ordering" calculation averages required quantities Glauber correlation functions applicable bosonic fields.