where is an observable occurring in a perturbed Hamiltonian, is an ensemble average and the dot above the A denotes the time derivative.[1]
For times that are greater than the correlation time of the fluctuations of the observable the transport coefficient obeys a generalized
Einstein relation:
^Water in Biology, Chemistry, and Physics: Experimental Overviews and Computational Methodologies, G. Wilse Robinson,
ISBN9789810224516, p. 80,
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^Kockmann, N. (2007). Transport Phenomena in Micro Process Engineering. Deutschland: Springer Berlin Heidelberg, page 66,
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