Quantum Brownian motion: The functional integral approach - Grabert, H.; Schramm, P.; Ingold, G.-L. (Elsevier)
The quantum mechanical dynamics of a particle coupled to a heat bath is treated by functional integral methods and a generalization of the Feynman-Vernon influence functional is derived. The extended theory describes the time evolution of nonfactorizing initial states and of equilibrium correlation functions. The theory is illuminated through exactly solvable models.
http://linkinghub.elsevier.com/retrieve/pii/0370-1573(88)90023-3
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