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Title: Particle decay in inflationary cosmology

Abstract

We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a prelude to a more general scenario, the method is applied here to study the decay of a particle in de Sitter inflation via a trilinear coupling to massless conformally coupled particles, both for wavelengths much larger and much smaller than the Hubble radius. For superhorizon modes we find that the decay is of the form {eta}{sup {gamma}{sub 1}} with {eta} being conformal time and we give an explicit expression for {gamma}{sub 1} to leading order in the coupling which has a noteworthy interpretation in terms of the Hawking temperature of de Sitter space-time. We show that if the mass M of the decaying field is <<H then the decay rate during inflation is enhanced over the Minkowski space-time result by a factor 2H/{pi}M. For wavelengths much smaller than the Hubble radius we find that the decay law is e with C({eta}) the scale factor and {alpha} determined by the strength of the trilinear coupling. In all cases we find a substantial enhancement in themore » decay law as compared to Minkowski space-time. These results suggest potential implications for the spectrum of scalar density fluctuations as well as non-Gaussianities.« less

Authors:
 [1];  [2];  [2];  [3];  [2];  [4]
  1. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
  2. (France)
  3. Laboratoire de Physique Theorique et Hautes Energies, Laboratoire Associe au CNRS UMR 7589, Universite Paris VI et Paris VII, Tour 24, 5'eme etage, 4 Place Jussieu, 75252 Paris, CEDEX 05 (France)
  4. (United States)
Publication Date:
OSTI Identifier:
20705200
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 70; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.70.063508; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGY; COUPLING; DE SITTER GROUP; FLUCTUATIONS; INFLATIONARY UNIVERSE; MINKOWSKI SPACE; PARTICLE DECAY; RELAXATION; RENORMALIZATION; SCALARS; SPACE-TIME; UNIVERSE

Citation Formats

Boyanovsky, D., Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, Laboratoire de Physique Theorique et Hautes Energies, Laboratoire Associe au CNRS UMR 7589, Universite Paris VI et Paris VII, Tour 24, 5'eme etage, 4 Place Jussieu, 75252 Paris, CEDEX 05, Vega, H.J. de, Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, and Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260. Particle decay in inflationary cosmology. United States: N. p., 2004. Web. doi:10.1103/PhysRevD.70.063508.
Boyanovsky, D., Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, Laboratoire de Physique Theorique et Hautes Energies, Laboratoire Associe au CNRS UMR 7589, Universite Paris VI et Paris VII, Tour 24, 5'eme etage, 4 Place Jussieu, 75252 Paris, CEDEX 05, Vega, H.J. de, Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, & Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260. Particle decay in inflationary cosmology. United States. doi:10.1103/PhysRevD.70.063508.
Boyanovsky, D., Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, Laboratoire de Physique Theorique et Hautes Energies, Laboratoire Associe au CNRS UMR 7589, Universite Paris VI et Paris VII, Tour 24, 5'eme etage, 4 Place Jussieu, 75252 Paris, CEDEX 05, Vega, H.J. de, Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris, and Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260. Wed . "Particle decay in inflationary cosmology". United States. doi:10.1103/PhysRevD.70.063508.
@article{osti_20705200,
title = {Particle decay in inflationary cosmology},
author = {Boyanovsky, D. and Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris and Laboratoire de Physique Theorique et Hautes Energies, Laboratoire Associe au CNRS UMR 7589, Universite Paris VI et Paris VII, Tour 24, 5'eme etage, 4 Place Jussieu, 75252 Paris, CEDEX 05 and Vega, H.J. de and Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61 Avenue de l'Observatoire, 75014 Paris and Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260},
abstractNote = {We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a prelude to a more general scenario, the method is applied here to study the decay of a particle in de Sitter inflation via a trilinear coupling to massless conformally coupled particles, both for wavelengths much larger and much smaller than the Hubble radius. For superhorizon modes we find that the decay is of the form {eta}{sup {gamma}{sub 1}} with {eta} being conformal time and we give an explicit expression for {gamma}{sub 1} to leading order in the coupling which has a noteworthy interpretation in terms of the Hawking temperature of de Sitter space-time. We show that if the mass M of the decaying field is <<H then the decay rate during inflation is enhanced over the Minkowski space-time result by a factor 2H/{pi}M. For wavelengths much smaller than the Hubble radius we find that the decay law is e with C({eta}) the scale factor and {alpha} determined by the strength of the trilinear coupling. In all cases we find a substantial enhancement in the decay law as compared to Minkowski space-time. These results suggest potential implications for the spectrum of scalar density fluctuations as well as non-Gaussianities.},
doi = {10.1103/PhysRevD.70.063508},
journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 6,
volume = 70,
place = {United States},
year = {2004},
month = {9}
}