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arXiv · hep-ph/9405396

Problems of Perturbation Series in Non-Equilibrium Quantum Field Theories

T. Altherr·D. Seibert
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Abstract

In the standard framework of non-equilibrium quantum field theories, the pinch singularities associated to multiple products of $δ$-functions do not cancel in a perturbative expansion unless the particle distributions are those for a system in thermal and chemical equilibrium.

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T. Altherr, D. Seibert. 1994-05-27. Problems of Perturbation Series in Non-Equilibrium Quantum Field Theories. https://doi.org/10.1016/0370-2693(94)91021-9

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