On the Langevin description of nonequilibrium quantum fields
arXiv:1209.1827 · doi:10.1103/PhysRevD.86.125002
Abstract
We consider the non-equilibrium dynamics of a real quantum scalar field. We show the formal equivalence of the exact evolution equations for the statistical and spectral two-point functions with a fictitious Langevin process and examine the conditions under which a local Markovian dynamics is a valid approximation. In quantum field theory, the memory kernel and the noise correlator typically exhibit long time power laws and are thus highly non-local, thereby questioning the possibility of a local description. We show that despite this fact, there is a finite time range during which a local description is accurate. This requires the theory to be (effectively) weakly coupled. We illustrate the use of such a local description for studies of decoherence and entropy production in quantum field theory.
15 pages, 3 figures, references added, typos corrected. To appear in Phys. Rev. D
References in corpus (12)
- Reheating in Inflationary Cosmology: Theory and Applications
- Lattice simulations of real-time quantum fields
- Low-cost fermions in classical field simulations
- Decoherence and entropy of primordial fluctuations. I: Formalism and interpretation
- Quantum field thermalization in expanding backgrounds
- Local Approximations for Effective Scalar Field Equations of Motion
- Comparison of Boltzmann Kinetics with Quantum Dynamics for a Chiral Yukawa Model Far From Equilibrium
- Quantum kinetic theory for fermions in temporally varying backrounds
- Thermal effects on slow-roll dynamics
- Particle creation and warm inflation
- Decoherence in an Interacting Quantum Field Theory: Thermal Case
- Quantum properties of a non-Gaussian state in the large-N approximation
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