Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2001-03-02
Physics
High Energy Physics
High Energy Physics - Phenomenology
18 pages, 1 Postscript figure, Latex
Scientific paper
We continue to study out of equilibrium TFT with switching on the interaction occurring at finite time. We exploit the concept of projected function (PF) and Wigner transform of projected function (WTPF). WTPF's are bare propagators, one-loop self-energies, retarded and advanced components of the resummed propagator. Among WTPF's convolution product is very simple, one does not need gradient expansion. However, WTPF's are completely determined by their infinite time limit and, thus, cannot be the carriers of relaxation phenomena. Furthermore, we observe that the functions capable of carrying relaxation phenomena (non-WTPF) emerge in the mixed ("ill-defined") products of retarded and advanced propagators and self-energies. In particular, only non-WTPF's contribute to time variation of equal-time Green functions (particle number, etc.); contributions from WTPF will be constant in time. As these are generated in mixed products, the pinching phenomenon is being promoted from an obstacle to the central feature of out of equilibrium TFT. We analyze the pinching phenomenon. In the case of naive pinching we reproduce known results. In Schwinger-Dyson equations the Keldysh component of self-energy is well defined even for multiple self-energy insertion contributions. We calaculate explicitly single self-energy contribution to Keldysh component of propagator which generates nontrivial time dependence. For photon production from QCD plasma (finite-lifetime effect) our approximate analytic results agree with the results by S. -Y. Wang and D. Boyanovsky obtained within dynamical renormalisation group approach.
No associations
LandOfFree
Pinching phenomenon: Central feature in out of equilibrium thermal field theories does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Pinching phenomenon: Central feature in out of equilibrium thermal field theories, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pinching phenomenon: Central feature in out of equilibrium thermal field theories will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-301404