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RESEARCH PRODUCT
Equilibrium and nonequilibrium many-body perturbation theory: a unified framework based on the Martin-Schwinger hierarchy
Gianluca StefanucciRobert Van Leeuwensubject
HistoryStatistical Mechanics (cond-mat.stat-mech)theoretical nanoscienceFOS: Physical sciencesNon-equilibrium thermodynamicsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectRotation formalisms in three dimensionsMany bodySettore FIS/03 - Fisica della MateriaComputer Science ApplicationsEducationFormalism (philosophy of mathematics)Boundary value problemCondensed Matter - Statistical MechanicsMathematicsMathematical physicsdescription
We present a unified framework for equilibrium and nonequilibrium many-body perturbation theory. The most general nonequilibrium many-body theory valid for general initial states is based on a time-contour originally introduced by Konstantinov and Perel'. The various other well-known formalisms of Keldysh, Matsubara and the zero-temperature formalism are then derived as special cases that arise under different assumptions. We further present a single simple proof of Wick's theorem that is at the same time valid in all these flavors of many-body theory. It arises simply as a solution of the equations of the Martin-Schwinger hierarchy for the noninteracting many-particle Green's function with appropriate boundary conditions. We further discuss a generalized Wick theorem for general initial states on the Keldysh contour and derive how the formalisms based on the Keldysh and Konstantinov-Perel'-contours are related for the case of general initial states.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-03-28 | Journal of Physics: Conference Series |