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Reynolds numbers in the early Universe

After electron-positron annihilation and prior to photon decoupling the magnetic Reynolds number is approximately twenty orders of magnitude larger than its kinetic counterpart which is, in turn, smaller than one. In this globally neutral system the large-scale inhomogeneities are provided by the sp...

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Autor principal: Giovannini, Massimo
Lenguaje:eng
Publicado: 2011
Materias:
Acceso en línea:https://dx.doi.org/10.1016/j.physletb.2012.04.007
http://cds.cern.ch/record/1400110
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author Giovannini, Massimo
author_facet Giovannini, Massimo
author_sort Giovannini, Massimo
collection CERN
description After electron-positron annihilation and prior to photon decoupling the magnetic Reynolds number is approximately twenty orders of magnitude larger than its kinetic counterpart which is, in turn, smaller than one. In this globally neutral system the large-scale inhomogeneities are provided by the spatial fluctuations of the scalar curvature. Owing to the analogy with the description of Markovian conducting fluids in the presence of acoustic fluctuations, the evolution equations of a putative magnetic field are averaged over the large-scale flow determined by curvature perturbations. General lessons are drawn on the typical diffusion scale of magnetic inhomogeneities. It is speculated that Reynolds numbers prior to electron-positron annihilation can be related to the entropy contained in the Hubble volume during the various stages of the evolution of the conducting plasma.
id cern-1400110
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2011
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spelling cern-14001102023-03-14T16:56:51Zdoi:10.1016/j.physletb.2012.04.007http://cds.cern.ch/record/1400110engGiovannini, MassimoReynolds numbers in the early UniverseAstrophysics and AstronomyAfter electron-positron annihilation and prior to photon decoupling the magnetic Reynolds number is approximately twenty orders of magnitude larger than its kinetic counterpart which is, in turn, smaller than one. In this globally neutral system the large-scale inhomogeneities are provided by the spatial fluctuations of the scalar curvature. Owing to the analogy with the description of Markovian conducting fluids in the presence of acoustic fluctuations, the evolution equations of a putative magnetic field are averaged over the large-scale flow determined by curvature perturbations. General lessons are drawn on the typical diffusion scale of magnetic inhomogeneities. It is speculated that Reynolds numbers prior to electron-positron annihilation can be related to the entropy contained in the Hubble volume during the various stages of the evolution of the conducting plasma.After electron–positron annihilation and prior to photon decoupling the magnetic Reynolds number is approximately twenty orders of magnitude larger than its kinetic counterpart which is, in turn, smaller than one. In this globally neutral system the large-scale inhomogeneities are provided by the spatial fluctuations of the scalar curvature. Owing to the analogy with the description of Markovian conducting fluids in the presence of acoustic fluctuations, the evolution equations of a putative magnetic field are averaged over the large-scale flow determined by curvature perturbations. General lessons are drawn on the typical diffusion scale of magnetic inhomogeneities. It is speculated that Reynolds numbers prior to electron–positron annihilation can be related to the entropy contained in the Hubble volume during the various stages of the evolution of the conducting plasma.After electron-positron annihilation and prior to photon decoupling the magnetic Reynolds number is approximately twenty orders of magnitude larger than its kinetic counterpart which is, in turn, smaller than one. In this globally neutral system the large-scale inhomogeneities are provided by the spatial fluctuations of the scalar curvature. Owing to the analogy with the description of Markovian conducting fluids in the presence of acoustic fluctuations, the evolution equations of a putative magnetic field are averaged over the large-scale flow determined by curvature perturbations. General lessons are drawn on the typical diffusion scale of magnetic inhomogeneities. It is speculated that Reynolds numbers prior to electron-positron annihilation can be related to the entropy contained in the Hubble volume during the various stages of the evolution of the conducting plasma.arXiv:1111.3867CERN-PH-TH-2011-281CERN-PH-TH-2011-281oai:cds.cern.ch:14001102011-11-17
spellingShingle Astrophysics and Astronomy
Giovannini, Massimo
Reynolds numbers in the early Universe
title Reynolds numbers in the early Universe
title_full Reynolds numbers in the early Universe
title_fullStr Reynolds numbers in the early Universe
title_full_unstemmed Reynolds numbers in the early Universe
title_short Reynolds numbers in the early Universe
title_sort reynolds numbers in the early universe
topic Astrophysics and Astronomy
url https://dx.doi.org/10.1016/j.physletb.2012.04.007
http://cds.cern.ch/record/1400110
work_keys_str_mv AT giovanninimassimo reynoldsnumbersintheearlyuniverse