Naslov
Two mechanisms for the elimination of pinch singularities in out of equilibrium thermal field theories

Autori
Dadić, Ivan

Izvornik
Physical review D (0556-2821) 59 (1999), 12;

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
pinching singularity; out of equilibrium; thermal field theory

Sažetak
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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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