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arXiv · 0710.4627

Functional renormalisation group approach to far-from-equilibrium quantum field dynamics

Thomas Gasenzer·Jan M. Pawlowski
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Abstract

Dynamic equations for quantum fields far from equilibrium are derived 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, and the time-evolution of the Green functions is computed within a vertex expansion. It is shown that this agrees with the dynamics derived from the 1/N-expansion of the two-particle irreducible effective action.

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Thomas Gasenzer, Jan M. Pawlowski. 2008-11-27. Functional renormalisation group approach to far-from-equilibrium quantum field dynamics. https://doi.org/10.1016/j.physletb.2008.10.049

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