Relaxation time of neutrinos in the early universe

Herrera, María; Hacyan, Shahen

doi:10.1086/167032

Cited by 37 publications

(66 citation statements)

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“…The total correction, evaluated with the above method, agrees with the recent result obtained in [34]. They also include the effect of finite temperature QED corrections to the equation of state of the electromagnetic plasma [35] and of residual coupling of neutrinos to the thermal bath during the e + -e − annihilation phase [13], [28]. However, the two combined corrections give a very small positive contribution, of the order δY p ≃ (2 ÷ 3)·10 −4 .…”

supporting

confidence: 82%

“…The interaction with the surrounding medium gives an extra plasma mass term to e + -e − , of the order of αT 2 /m e , which slightly changes the neutrino to photon temperature ratio. Actually it has been shown that there is a residual small coupling of neutrinos at the electron-positron annihilation phase, which introduces non equilibrium effects in the neutrino energy distribution [13], [28]. This last effect introduces corrections to 4 He abundance of the order of (1 ÷ 2)·10 −4 .…”

Section: Introductionmentioning

confidence: 99%

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Precision rates for nucleon weak interactions in primordial nucleosynthesis and 4He abundance

et al. 1999

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We report the results of a detailed calculation of nucleon weak interactions relevant for the neutron to proton density ratio at the onset of primordial nucleosynthesis. Radiative electromagnetic corrections, finite nucleon mass terms, thermal radiative effects on weak processes and on neutrino temperature are taken into account to reduce the theoretical uncertainty on n ↔ p rates to 1%. This translates into a sensitivity in 4 He mass fraction Y p prediction up to 10 −4 . We find a positive total correction to the Born prediction δY p ≃ 0.004.

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supporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Precision rates for nucleon weak interactions in primordial nucleosynthesis and 4He abundance

et al. 1999

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“…Early work [1][2][3][4] considered the neutrinos to have a thermal distribution after weak decoupling and calculated the consequences of e ± annihilation on the temperature of this thermal distribution. The focus of Refs.…”

Section: Discussionmentioning

confidence: 99%

“…Refs. [3,4] treated the neutrinos and the electrons/positrons as two relativistic gases with different temperatures and calculated the relaxation time over which these two components of the universe would return toward thermal equilibrium.…”

Section: Discussionmentioning

confidence: 99%

“…The work we describe here builds on the many previous studies of the evolution of the neutrino energy distribution functions in the early universe (see Refs. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and Appendix A). Higher precision in theoretical calculations of neutrino transport and nucleosynthesis in the early universe is warranted by recent and anticipated improvement in the precision of cosmological observations.…”

Section: Introductionmentioning

confidence: 99%

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Neutrino energy transport in weak decoupling and big bang nucleosynthesis

et al. 2016

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We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the νe,νe, νµ,νµ, ντ ,ντ energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for: the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter N eff . We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium. These changes are potentially significant in the context of anticipated improvements in obversational and nuclear physics uncertainties.PACS numbers: 95.85.Ry,14.60.Lm,26.35.+c,98.70.Vc

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Early Universe and Big Bang Nucleosynthesis

Rana

1990

Quark—Gluon Plasma

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Relaxation time of neutrinos in the early universe

Cited by 37 publications

References 0 publications

Precision rates for nucleon weak interactions in primordial nucleosynthesis and 4He abundance

Precision rates for nucleon weak interactions in primordial nucleosynthesis and 4He abundance

Neutrino energy transport in weak decoupling and big bang nucleosynthesis

Early Universe and Big Bang Nucleosynthesis

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