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arXiv · 1306.6519

Construction of KMS States in Perturbative QFT and Renormalized Hamiltonian Dynamics

Klaus Fredenhagen·Falk Lindner
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Abstract

We present a general construction of KMS states in the framework of perturbative algebraic quantum field theory (pAQFT). Our approach may be understood as an extension of the Schwinger-Keldysh formalism. We obtain in particular the Wightman functions at positive temperature, thus solving a problem posed some time ago by Steinmann. The notorious infrared divergences observed in a diagrammatic expansion are shown to be absent due to a consequent exploitation of the locality properties of pAQFT. To this avail, we introduce a novel, Hamiltonian description of the interacting dynamics and find, in particular, a precise relation between relativistic QFT and rigorous quantum statistical mechanics.

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Klaus Fredenhagen, Falk Lindner. 2014-05-13. Construction of KMS States in Perturbative QFT and Renormalized Hamiltonian Dynamics. https://doi.org/10.1007/s00220-014-2141-7

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