论文标题
从早期宇宙到当前宇宙的中微子解耦的评论
A review of neutrino decoupling from the early universe to the current universe
论文作者
论文摘要
我们回顾了由于早期宇宙中与电子，正电子和中微子的相互作用而引起的遗物中微子光谱的扭曲。我们为中微子密度矩阵求解了多个分化的动力学方程，包括真空中微子中微子振荡，电子和正电子背景的振荡，对电子质量和电磁等离子体的碰撞项和有限的温度校正，以及接下来的$ \ nath Calcal $ \ \ nathcal calcal。之后，我们估算了中微子脱耦的光谱扭曲对当前宇宙中宇宙中微子背景（c $ν$ b）的数量密度和能量密度的影响，并讨论了这些影响在直接检测c $ν$ b对tritium tritium的捕获率的含义，并强调了Ptolememy-type-type-type-type-type type type type type type。此外，我们发现有效数量中微子的精确值，$ n _ {\ rm eff} = 3.044 $。但是，QED在$ \ MATHCAL {O}（E^2 G_F^2）$上对弱交互率进行了校正，并通过其自我相互作用的中微子向前散射在迄今为止的整个文献中尚未确切考虑到整个文献中。最近的研究表明，这些忽视可能导致$ n _ {\ rm eff} $中的$ \ pm（10^{ - 3} -10^{ - 4}）$的不确定性。
We review the distortions of spectra of relic neutrinos due to the interactions with electrons, positrons, and neutrinos in the early universe. We solve integro-differential kinetic equations for the neutrino density matrix, including vacuum three-flavor neutrino oscillations, oscillations in electron and positron background, a collision term and finite temperature corrections to electron mass and electromagnetic plasma up to the next-to-leading order $\mathcal{O}(e^3)$. After that, we estimate the effects of the spectral distortions in neutrino decoupling on the number density and energy density of the Cosmic Neutrino Background (C$ν$B) in the current universe, and discuss the implications of these effects on the capture rates in direct detection of the C$ν$B on tritium, with emphasis on the PTOLEMY-type experiment. In addition, we find a precise value of the effective number of neutrinos, $N_{\rm eff}=3.044$. However, QED corrections to weak interaction rates at order $\mathcal{O}(e^2 G_F^2)$ and forward scattering of neutrinos via their self-interactions have not been precisely taken into account in the whole literature so far. Recent studies suggest that these neglections might induce uncertainties of $\pm(10^{-3} - 10^{-4})$ in $N_{\rm eff}$.
