کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1857606 | 1529926 | 2009 | 27 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Nonequilibrium dynamics of scalar fields in a thermal bath Nonequilibrium dynamics of scalar fields in a thermal bath](/preview/png/1857606.png)
We study the approach to equilibrium for a scalar field which is coupled to a large thermal bath. Our analysis of the initial value problem is based on Kadanoff-Baym equations which are shown to be equivalent to a stochastic Langevin equation. The interaction with the thermal bath generates a temperature-dependent spectral density, either through decay and inverse decay processes or via Landau damping. In equilibrium, energy density and pressure are determined by the Bose–Einstein distribution function evaluated at a complex quasi-particle pole. The time evolution of the statistical propagator is compared with solutions of the Boltzmann equations for particles as well as quasi-particles. The dependence on initial conditions and the range of validity of the Boltzmann approximation are determined.
Journal: Annals of Physics - Volume 324, Issue 6, June 2009, Pages 1234–1260