Choice of initial states in nonequilibrium dynamics

We study the renormalization problem for the Hartree-Fock approximation of the ON invariant 4 model in the symmetric phase and show how to systematically improve the corresponding diagrammatic resummation to achieve the correct renormalization properties of the effective field equations, including renormalization-group invariance with the one-loop beta function. These new Hartree-Fock dynamics is still of a mean-field type but includes memory effects which are generically nonlocal also in space.

Section: Other Initial States and Nonzero Temperaturesmentioning

confidence: 99%

Renormalized and renormalization-group invariant Hartree-Fock approximation

Destri

Sartirana

2005

“…Nonequilibrium quantum field theory has seen a tremendous progress, after seminal publications in the 1980's [38], mainly in the last decade [20,39,40,41,42,45,46]. The main ingredient, besides the CTP formalism itself, are various approximations based on variational principles.…”

Section: Effective Action a Quantum Fluctuations And Their Non-mentioning

confidence: 99%

Out-of-equilibrium evolution of quantum fields in the hybrid model with quantum back reaction

Baacke¹,

Heinen²

2004

Self Cite

The hybrid model with a scalar "inflaton" field coupled to a "Higgs" field with a broken symmetry potential is one of the promising models for inflation and (p)reheating after inflation. We consider the nonequilibrium evolution of the quantum fields of this model with quantum back reaction in the Hartree approximation, in particular the transition of the Higgs field from the metastable "false vacuum" to the broken symmetry phase. We have performed the renormalization of the equations of motion, of the gap equations and of the energy density, using dimensional regularization. We study the influence of the back reaction on the evolution of the classical fields and of the quantum fluctuations. We observe that back reaction plays an important role over a wide range of parameters. Some implications of our investigation for the preheating stage after cosmic inflation are presented.

“…During the oscillations of the background fields φ and N, particles can be produced by parametric resonance (preheating) [23,24,25] much before the inflaton has time to decay perturbatively, being this in general a more efficient mechanism of particle production than standard perturbative decay.…”

Section: Preheating/reheatingmentioning

confidence: 99%

Leptogenesis in a realistic supersymmetric model of inflation with a low reheat temperature

Bastero-Gil

King

2001

We discuss leptogenesis in a realistic supersymmetric model of inflation with a low reheat temperature 1-10 GeV. The lepton asymmetry is generated by a decaying right handed sneutrino, which is produced after inflation during preheating. The inflationary model is based on a simple variant of the Next-to-Minimal Supersymmetric Standard model (NMSSM) which solves the µ problem, called φNMSSM, where the additional singlet φ plays the role of the inflaton in hybrid (or inverted hybrid) type models. The model is invariant under an approximate Peccei-Quinn symmetry which also solves the strong CP problem, and leads to an invisible axion with interesting cosmological consequences. We show how the baryon number of the universe and the nature of cold dark matter are determined by the same parameters controlling the strong CP problem, the µ problem and the neutrino masses and mixing angles.