English

Staying Thermal with Hartree Ensemble Approximations

High Energy Physics - Phenomenology 2015-06-25 v2 High Energy Physics - Lattice

Abstract

We study thermal behavior of a recently introduced Hartree ensemble approximation, which allows for non-perturbative inhomogeneous field configurations as well as for approximate thermalization, in the ϕ4\phi^4 model in 1+1 dimensions. Using ensembles with a free field thermal distribution as out-of-equilibrium initial conditions we determine thermalization time scales. The time scale for which the system stays in approximate quantum thermal equilibrium is an indication of the time scales for which the approximation method stays reasonable. This time scale turns out to be two orders of magnitude larger than the time scale for thermalization, in the range of couplings and temperatures studied. We also discuss simplifications of our method which are numerically more efficient and make a comparison with classical dynamics.

Keywords

Cite

@article{arxiv.hep-ph/0012362,
  title  = {Staying Thermal with Hartree Ensemble Approximations},
  author = {M. Salle and J. Smit and J. C. Vink},
  journal= {arXiv preprint arXiv:hep-ph/0012362},
  year   = {2015}
}

Comments

19 pages latex; extensively rewritten to improve presentation, data essentially unchanged, analysis sharpened and one table added

R2 v1 2026-07-22T13:31:20.643Z