Darmstadt 2008 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 27: Poster Quantengase

Q 27.28: Poster

Dienstag, 11. März 2008, 16:30–19:00, Poster C2

Functional renormalisation group approach to far-from-equilibrium quantum field dynamics — •Stefan Keßler, Jan M. Pawlowski, and Thomas Gasenzer — Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg

We present a derivation of dynamic equations for quantum fields far from equilibrium by use of functional renormalisation group techniques. The obtained equations are non-perturbative and lead substantially beyond mean-field and quantum Boltzmann type approximations. The approach is based on a regularised version of the generating functional for correlation functions, where times greater than a chosen cutoff time are suppressed. As a central result a time evolution equation for the non-equilibrium effective action is derived. The time evolution of Green functions is computed within a vertex expansion. In a truncation of the flow equations the dynamic equations as known from the 1/N-expansion of the 2PI effective interaction are recovered.