Journal article

Publication year: 1999

Pages: 517-522

Journal: The European Physical Journal C

Volume number: 8

Issue number: 3

ISSN: 1434-6044

eISSN: 1434-6052

DOI Link: https://doi.org/10.1007/s100529901095

Publisher: SpringerOpen

Abstract: 
Ill-defined pinch singularities arising in a perturbative expansion in out of equilibrium quantum field theory have a natural analogue to standard scattering theory. We explicitly demonstrate that the occurrence of such terms is directly related to Fermi's golden rule known from elementary scattering theory and is thus of no mystery. We further argue that within the process of thermalization of a plasma one has to resum such contributions to all orders as the process itself is of non-perturbative nature. In this way the resummed propagators obtain a finite width. Within the Markov approximation of kinetic theory the actual phase space distribution at a given time of the evolution enters explicitly.

Harvard Citation style: Greiner, C. and Leupold, S. (1999) Interpretation and resolution of pinch singularities in non-equilibrium quantum field theory, The European Physical Journal C, 8(3), pp. 517-522. https://doi.org/10.1007/s100529901095

APA Citation style: Greiner, C., & Leupold, S. (1999). Interpretation and resolution of pinch singularities in non-equilibrium quantum field theory. The European Physical Journal C. 8(3), 517-522. https://doi.org/10.1007/s100529901095