The European Physical Journal A

, Volume 31, Issue 4, pp 883–885 | Cite as

Out-of-equilibrium quantum field dynamics in external fields

  • F. J. CaoEmail author
QNP 2006


The quantum dynamics of the symmetry-broken λ(Φ 2)2 scalar-field theory in the presence of an homogeneous external field is investigated in the large-N limit. We consider an initial thermal state of temperature T for a constant external field J. A subsequent sign flip of the external field, J→ - J, gives rise to an out-of-equilibrium nonperturbative quantum field dynamics. We review here the dynamics for the symmetry-broken λ(Φ 2)2 scalar N component field theory in the large-N limit, with particular stress in the comparison between the results when the initial temperature is zero and when it is finite. The presence of a finite temperature modifies the dynamical effective potential for the expectation value, and also makes that the transition between the two regimes of the early dynamics occurs for lower values of the external field. The two regimes are characterized by the presence or absence of a temporal trapping close to the metastable equilibrium position of the potential. In the cases when the trapping occurs it is shorter for larger initial temperatures.


11.10.Wx Finite-temperature field theory 11.15.Pg Expansions for large numbers of components (e.g. , 1/Nc expansions) 11.30.Qc Spontaneous and radiative symmetry breaking 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J.W. Harris, B. Muller, Annu. Rev. Nucl. Part. Sci. 46, 71 (1996)CrossRefADSGoogle Scholar
  2. 2.
    F.J. Cao, H.J. de Vega, N.G. Sánchez, Phys. Rev. D 70, 083528 (2004)CrossRefADSMathSciNetGoogle Scholar
  3. 3.
    F.J. Cao, H.J. de Vega, Phys. Rev. D 65, 045012 (2002).CrossRefADSGoogle Scholar
  4. 4.
    F.J. Cao, M. Feito, Phys. Rev. D 73, 045017 (2006).CrossRefADSGoogle Scholar
  5. 5.
    M. Le Bellac, Thermal Field Theory (Cambridge University Press, New York, 2000).Google Scholar
  6. 6.
    J. Berges, Nucl. Phys. A 699, 847 (2002)zbMATHCrossRefADSGoogle Scholar

Copyright information

© Società Italiana di Fisica and Springer-Verlag 2007

Authors and Affiliations

  1. 1.Departamento Fısica Atómica, Molecular y NuclearUniversidad Complutense de MadridMadridSpain
  2. 2.Laboratoire Associé au CNRS UMR 8112LERMA, Observatoire de ParisParisFrance

Personalised recommendations