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Title: Nonlinear inflaton fragmentation after preheating

Abstract

We consider the nonlinear dynamics of inflaton fragmentation during and after preheating in the simplest model of chaotic inflation. While the earlier regime of parametric resonant particle production and the later turbulent regime of interacting fields evolving towards equilibrium are well identified and understood, the short intermediate stage of violent nonlinear dynamics remains less explored. Lattice simulations of fully nonlinear preheating dynamics show specific features of this intermediate stage: occupation numbers of the scalar particles are peaked, scalar fields become significantly nongaussian and the field dynamics become chaotic and irreversible. Visualization of the field dynamics in position space reveals that nonlinear interactions generate nongaussian inflaton inhomogeneities with very fast growing amplitudes. The peaks of the inflaton inhomogeneities coincide with the peaks of the scalar field(s) produced by parametric resonance. When the inflaton peaks reach their maxima, they stop growing and begin to expand. The subsequent dynamics is determined by expansion and superposition of the scalar waves originating from the peaks. Multiple wave superposition results in phase mixing and turbulent wave dynamics. Thus, the short intermediate stage is defined by the formation, expansion and collision of bubblelike field inhomogeneities associated with the peaks of the original gaussian field. This process ismore » qualitatively similar to the bubblelike inflaton fragmentation that occurs during tachyonic preheating after hybrid or new inflation.« less

Authors:
 [1];  [2]
  1. Department of Physics, Clark Science Center, Smith College Northampton, Massachusetts 01063 (United States)
  2. CITA, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)
Publication Date:
OSTI Identifier:
21011061
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevD.75.043518; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; CHAOS THEORY; COMPUTERIZED SIMULATION; COSMOLOGY; INFLATIONARY UNIVERSE; LATTICE FIELD THEORY; NONLINEAR PROBLEMS; PARTICLE PRODUCTION; SCALAR FIELDS; TACHYONS

Citation Formats

Felder, Gary N., and Kofman, Lev. Nonlinear inflaton fragmentation after preheating. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.043518.
Felder, Gary N., & Kofman, Lev. Nonlinear inflaton fragmentation after preheating. United States. doi:10.1103/PHYSREVD.75.043518.
Felder, Gary N., and Kofman, Lev. Thu . "Nonlinear inflaton fragmentation after preheating". United States. doi:10.1103/PHYSREVD.75.043518.
@article{osti_21011061,
title = {Nonlinear inflaton fragmentation after preheating},
author = {Felder, Gary N. and Kofman, Lev},
abstractNote = {We consider the nonlinear dynamics of inflaton fragmentation during and after preheating in the simplest model of chaotic inflation. While the earlier regime of parametric resonant particle production and the later turbulent regime of interacting fields evolving towards equilibrium are well identified and understood, the short intermediate stage of violent nonlinear dynamics remains less explored. Lattice simulations of fully nonlinear preheating dynamics show specific features of this intermediate stage: occupation numbers of the scalar particles are peaked, scalar fields become significantly nongaussian and the field dynamics become chaotic and irreversible. Visualization of the field dynamics in position space reveals that nonlinear interactions generate nongaussian inflaton inhomogeneities with very fast growing amplitudes. The peaks of the inflaton inhomogeneities coincide with the peaks of the scalar field(s) produced by parametric resonance. When the inflaton peaks reach their maxima, they stop growing and begin to expand. The subsequent dynamics is determined by expansion and superposition of the scalar waves originating from the peaks. Multiple wave superposition results in phase mixing and turbulent wave dynamics. Thus, the short intermediate stage is defined by the formation, expansion and collision of bubblelike field inhomogeneities associated with the peaks of the original gaussian field. This process is qualitatively similar to the bubblelike inflaton fragmentation that occurs during tachyonic preheating after hybrid or new inflation.},
doi = {10.1103/PHYSREVD.75.043518},
journal = {Physical Review. D, Particles Fields},
number = 4,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}