The 2PI coupling expansion revisited

Abstract

Recently, out-of-equilibrium field theory has been studied using approximations based on truncations of the 2PI effective action. Although results are promising, the convergence of subsequent orders of the approximation is difficult to get a handle on, mainly because, generically, only the lowest non-trivial order is currently numerically tractable. We study one specific case, the broken phase of the phi^4 model, where the existence of an effective three point vertex makes it possible to compare a lowest and next-to-lowest non-trivial order.

5 pages, 4 figures. To appear in the proceedings of XQCD, Swansea, 2-5 August 2005

References in corpus (5)

• Far-from-equilibrium dynamics with broken symmetries from the 2PI-1/N expansion
• Parametric resonance in quantum field theory
• Thermalization of fermionic quantum fields
• Nonequilibrium time evolution of the spectral function in quantum field theory
• Tachyonic preheating using 2PI-1/N dynamics and the classical approximation