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Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe

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Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe. / Brandenberger, Robert; Mazumdar, Anupam.
In: Journal of Cosmology and Astroparticle Physics, Vol. 2004, No. 8, 15, 24.08.2004.

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Harvard

Brandenberger, R & Mazumdar, A 2004, 'Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe', Journal of Cosmology and Astroparticle Physics, vol. 2004, no. 8, 15. https://doi.org/10.1088/1475-7516/2004/08/015

APA

Vancouver

Brandenberger R, Mazumdar A. Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe. Journal of Cosmology and Astroparticle Physics. 2004 Aug 24;2004(8):15. doi: 10.1088/1475-7516/2004/08/015

Author

Brandenberger, Robert ; Mazumdar, Anupam. / Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe. In: Journal of Cosmology and Astroparticle Physics. 2004 ; Vol. 2004, No. 8.

Bibtex

@article{789f6ec625ba42f4a2126b4d0ec861ac,
title = "Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe",
abstract = "In this Letter we discuss the issues of the graceful exit from inflation and of matter creation in the context of a recent scenario \cite{RHBrev} in which the back-reaction of long wavelength cosmological perturbations induces a negative contribution to the cosmological constant and leads to a dynamical relaxation of the bare cosmological constant. The initially large cosmological constant gives rise to primordial inflation, during which cosmological perturbations are stretched beyond the Hubble radius. The cumulative effect of the long wavelength fluctuations back-reacts on the background geometry in a form which corresponds to the addition of a negative effective cosmological constant to the energy-momentum tensor. In the absence of an effective scalar field driving inflation, whose decay can reheat the Universe, the challenge is to find a mechanism which produces matter at the end of the relaxation process. In this Letter, we point out that the decay of a condensate representing the order parameter for a ``flat'' direction in the field theory moduli space can naturally provide a matter generation mechanism. The order parameter is displaced from its vacuum value by thermal or quantum fluctuations, it is frozen until the Hubble constant drops to a sufficiently low value, and then begins to oscillate about its ground state. During the period of oscillation it can decay into Standard Model particles similar to how the inflaton decays in scalar-field-driven models of inflation.",
keywords = "inflation, physics of the early universe, dark energy theory",
author = "Robert Brandenberger and Anupam Mazumdar",
note = "6 pages",
year = "2004",
month = aug,
day = "24",
doi = "10.1088/1475-7516/2004/08/015",
language = "English",
volume = "2004",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing",
number = "8",

}

RIS

TY - JOUR

T1 - Dynamical Relaxation of the Cosmological Constant and Matter Creation in the Universe

AU - Brandenberger, Robert

AU - Mazumdar, Anupam

N1 - 6 pages

PY - 2004/8/24

Y1 - 2004/8/24

N2 - In this Letter we discuss the issues of the graceful exit from inflation and of matter creation in the context of a recent scenario \cite{RHBrev} in which the back-reaction of long wavelength cosmological perturbations induces a negative contribution to the cosmological constant and leads to a dynamical relaxation of the bare cosmological constant. The initially large cosmological constant gives rise to primordial inflation, during which cosmological perturbations are stretched beyond the Hubble radius. The cumulative effect of the long wavelength fluctuations back-reacts on the background geometry in a form which corresponds to the addition of a negative effective cosmological constant to the energy-momentum tensor. In the absence of an effective scalar field driving inflation, whose decay can reheat the Universe, the challenge is to find a mechanism which produces matter at the end of the relaxation process. In this Letter, we point out that the decay of a condensate representing the order parameter for a ``flat'' direction in the field theory moduli space can naturally provide a matter generation mechanism. The order parameter is displaced from its vacuum value by thermal or quantum fluctuations, it is frozen until the Hubble constant drops to a sufficiently low value, and then begins to oscillate about its ground state. During the period of oscillation it can decay into Standard Model particles similar to how the inflaton decays in scalar-field-driven models of inflation.

AB - In this Letter we discuss the issues of the graceful exit from inflation and of matter creation in the context of a recent scenario \cite{RHBrev} in which the back-reaction of long wavelength cosmological perturbations induces a negative contribution to the cosmological constant and leads to a dynamical relaxation of the bare cosmological constant. The initially large cosmological constant gives rise to primordial inflation, during which cosmological perturbations are stretched beyond the Hubble radius. The cumulative effect of the long wavelength fluctuations back-reacts on the background geometry in a form which corresponds to the addition of a negative effective cosmological constant to the energy-momentum tensor. In the absence of an effective scalar field driving inflation, whose decay can reheat the Universe, the challenge is to find a mechanism which produces matter at the end of the relaxation process. In this Letter, we point out that the decay of a condensate representing the order parameter for a ``flat'' direction in the field theory moduli space can naturally provide a matter generation mechanism. The order parameter is displaced from its vacuum value by thermal or quantum fluctuations, it is frozen until the Hubble constant drops to a sufficiently low value, and then begins to oscillate about its ground state. During the period of oscillation it can decay into Standard Model particles similar to how the inflaton decays in scalar-field-driven models of inflation.

KW - inflation

KW - physics of the early universe

KW - dark energy theory

U2 - 10.1088/1475-7516/2004/08/015

DO - 10.1088/1475-7516/2004/08/015

M3 - Journal article

VL - 2004

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 8

M1 - 15

ER -