5 papers · 1 filter
On the Non-Equilibrium Early Universe
P. Elmfors, K. Enqvist, I. Vilja
We study non--equilibrium ensemble corrections to particle masses and the effective potential in the early universe, using a uniform momentum distribution as an example. The result…
Real-Time Thermal Propagators and the QED Effective Action for an External Magnetic Field
P. Elmfors, D. Persson, B. -S. Skagerstam
The thermal averaged real-time propagator of a Dirac fermion in a static uniform magnetic field is derived. At non-zero chemical potential and temperature we find explicitly th…
Thermalization of the Higgs Field at the Electroweak Phase Transition
Per Elmfors, Kari Enqvist, Iiro Vilja
The thermalization rate for long wavelength fluctuations in the Higgs field is calculated from the imaginary part of the finite temperature effective action in the unbroken phase o…
Generalizations of the thermal Bogoliubov transformation
P. Elmfors, H. Umezawa
The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the --degree of freedom to tilde non--conserving repres…
Finite temperature effective action and thermalization of perturbations
Per Elmfors, Kari Enqvist, Iiro Vilja
The effective action is computed for the \lphi--theory at finite temperature for small perturbations about a constant background field, using a generalized tadpole method. We find…