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Out of equilibrium thermal field theories — Elimination of pinching singularities

  • Ivan Dadić
Conference paper
Part of the Lecture Notes in Physics book series (LNP, volume 516)

Abstract

We analyze ill-defined pinch singularities characteristic of out of equilibrium thermal field theories. We identify two mechanisms that eliminate pinching even at the single self-energy insertion approximation to the propagator: the first is based on the vanishing of phase space at the singular point (threshold effect). It is effective in QED with a massive electron and a massless photon. In massless QCD, this mechanism fails, but the pinches cancel owing to the second mechanism, i.e., owing to the spinor/tensor structure of the single self-energy insertion contribution to the propagator. The constraints imposed on distribution functions are very reasonable. The same mechanism eliminates pinching from the resummed Schwinger-Dyson series.

Keywords

Mass Shell Gluon Propagator Massless Quark Collinear Singularity Ghost Propagator 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  • Ivan Dadić
    • 1
  1. 1.Ruder Bošković InstituteZagrebCroatia

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