Parametric resonance in the early Universe—a fitting analysis
Abstract
Particle production via parametric resonance in the early Universe, is a nonperturbative, nonlinear and outofequilibrium phenomenon. Although it is a well studied topic, whenever a new scenario exhibits parametric resonance, a full reanalysis is normally required. To avoid this tedious task, many works present often only a simplified linear treatment of the problem. In order to surpass this circumstance in the future, we provide a fitting analysis of parametric resonance through all its relevant stages: initial linear growth, nonlinear evolution, and relaxation towards equilibrium. Using lattice simulations in an expanding grid in 3+1 dimensions, we parametrize the dynamics' outcome scanning over the relevant ingredients: role of the oscillatory field, particle coupling strength, initial conditions, and background expansion rate. We emphasize the inaccuracy of the linear calculation of the decay time of the oscillatory field, and propose a more appropriate definition of this scale based on the subsequent nonlinear dynamics. We provide simple fits to the relevant time scales and particle energy fractions at each stage. Our fits can be applied to postinflationary preheating scenarios, where the oscillatory field is the inflaton, or to spectatorfield scenarios, where the oscillatory field can be e.g. a curvaton, or the Standard Model Higgs.
 Authors:
 Theoretical Physics Department, CERN, Geneva (Switzerland)
 Instituto de Física Teórica IFTUAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid (Spain)
 Publication Date:
 OSTI Identifier:
 22680051
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COMPUTERIZED SIMULATION; COUPLING; EQUILIBRIUM; EVOLUTION; EXPANSION; FIELD THEORIES; HIGGS BOSONS; HIGGS MODEL; INFLATONS; NONLINEAR PROBLEMS; PARTICLE DECAY; PARTICLE PRODUCTION; RELAXATION; RESONANCE; STANDARD MODEL; UNIVERSE
Citation Formats
Figueroa, Daniel G., and Torrentí, Francisco, Email: daniel.figueroa@cern.ch, Email: f.torrenti@csic.es. Parametric resonance in the early Universe—a fitting analysis. United States: N. p., 2017.
Web. doi:10.1088/14757516/2017/02/001.
Figueroa, Daniel G., & Torrentí, Francisco, Email: daniel.figueroa@cern.ch, Email: f.torrenti@csic.es. Parametric resonance in the early Universe—a fitting analysis. United States. doi:10.1088/14757516/2017/02/001.
Figueroa, Daniel G., and Torrentí, Francisco, Email: daniel.figueroa@cern.ch, Email: f.torrenti@csic.es. Wed .
"Parametric resonance in the early Universe—a fitting analysis". United States.
doi:10.1088/14757516/2017/02/001.
@article{osti_22680051,
title = {Parametric resonance in the early Universe—a fitting analysis},
author = {Figueroa, Daniel G. and Torrentí, Francisco, Email: daniel.figueroa@cern.ch, Email: f.torrenti@csic.es},
abstractNote = {Particle production via parametric resonance in the early Universe, is a nonperturbative, nonlinear and outofequilibrium phenomenon. Although it is a well studied topic, whenever a new scenario exhibits parametric resonance, a full reanalysis is normally required. To avoid this tedious task, many works present often only a simplified linear treatment of the problem. In order to surpass this circumstance in the future, we provide a fitting analysis of parametric resonance through all its relevant stages: initial linear growth, nonlinear evolution, and relaxation towards equilibrium. Using lattice simulations in an expanding grid in 3+1 dimensions, we parametrize the dynamics' outcome scanning over the relevant ingredients: role of the oscillatory field, particle coupling strength, initial conditions, and background expansion rate. We emphasize the inaccuracy of the linear calculation of the decay time of the oscillatory field, and propose a more appropriate definition of this scale based on the subsequent nonlinear dynamics. We provide simple fits to the relevant time scales and particle energy fractions at each stage. Our fits can be applied to postinflationary preheating scenarios, where the oscillatory field is the inflaton, or to spectatorfield scenarios, where the oscillatory field can be e.g. a curvaton, or the Standard Model Higgs.},
doi = {10.1088/14757516/2017/02/001},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 02,
volume = 2017,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}

Parametric resonance has been discussed as a mechanism for copious particle production following inflation. Here we present a simple and intuitive calculational method for estimating the efficiency of parametric amplification as a function of parameters. This is important for determining whether resonant amplification plays an important role in the reheating process. We find that significant amplification occurs only for a limited range of couplings and interactions. {copyright} {ital 1998} {ital The American Physical Society}

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