Effective Field Theory out of Equilibrium: Brownian quantum fields

  title={Effective Field Theory out of Equilibrium: Brownian quantum fields},
  author={Daniel Boyanovsky},
  journal={arXiv: High Energy Physics - Phenomenology},
  • D. Boyanovsky
  • Published 28 February 2015
  • Physics
  • arXiv: High Energy Physics - Phenomenology
The emergence of an effective field theory out of equilibrium is studied in the case in which a light field --the system-- interacts with very heavy fields in a finite temperature bath. We obtain the reduced density matrix for the light field, its time evolution is determined by an effective action that includes the \emph{influence action} from correlations of the heavy degrees of freedom. The non-equilibrium effective field theory yields a Langevin equation of motion for the light field in… 

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