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arXiv · 1704.01392

Discrete-time construction of nonequilibrium path integrals on the Kostantinov-Perel' time contour

Andrea Secchi·Marco Polini
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Abstract

Rigorous nonequilibrium actions for the many-body problem are usually derived by means of path integrals combined with a discrete temporal mesh on the Schwinger-Keldysh time contour. The latter suffers from a fundamental limitation: the initial state on this contour cannot be arbitrary, but necessarily needs to be described by a non-interacting density matrix, while interactions are switched on adiabatically. The Kostantinov-Perel' contour overcomes these and other limitations, allowing generic initial-state preparations. In this Article, we apply the technique of the discrete temporal mesh to rigorously build the nonequilibrium path integral on the Kostantinov-Perel' time contour.

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Andrea Secchi, Marco Polini. 2017-04-05. Discrete-time construction of nonequilibrium path integrals on the Kostantinov-Perel' time contour. https://doi.org/10.1088/1751-8121/ab2080

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