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

Understand

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.