论文标题
遗物中微子解耦的精确计算
A precision calculation of relic neutrino decoupling
论文作者
论文摘要
我们研究了由于早期宇宙中与电子，正上微子和中微子的相互作用而导致的遗物中微子平衡光谱的扭曲。我们为中微子密度矩阵求解了不差的动力学方程，包括三种培养基振荡和第一次从QED到近s-Mathcal $ \ Mathcal {O}（E^3）$的有限温度校正。此外，直接解决了中微子的质量基础上的等效动力学方程，并且我们在质量基础上也可以在数值上评估中微子光谱的扭曲，这些中微子光谱很容易被外推到当前宇宙中非偏见的中微子的畸变。在这两个基础上，我们都发现有效数量中微子的值相同，$ n _ {\ rm eff} = 3.044 $，该值分析了总中微子能量密度。 $ n _ {\ rm eff} $的估计误差由于数值计算和中微子混合参数的选择最多为0.0005。
We study the distortions of equilibrium spectra of relic neutrinos due to the interactions with electrons, positrons, and neutrinos in the early Universe. We solve the integro-differential kinetic equations for the neutrino density matrix, including three-flavor oscillations and finite temperature corrections from QED up to the next-to-leading order $\mathcal{O}(e^3)$ for the first time. In addition, the equivalent kinetic equations in the mass basis of neutrinos are directly solved, and we numerically evaluate the distortions of the neutrino spectra in the mass basis as well, which can be easily extrapolated into those for non-relativistic neutrinos in the current Universe. In both bases, we find the same value of the effective number of neutrinos, $N_{\rm eff} = 3.044$, which parameterizes the total neutrino energy density. The estimated error for the value of $N_{\rm eff}$ due to the numerical calculations and the choice of neutrino mixing parameters would be at most 0.0005.
