物理
宇宙微波背景
中微子
大爆炸核合成
天体物理学
重子
粒子物理学
核合成
欧米茄
航程(航空)
丰度(生态学)
超出标准模型的物理
化学元素丰度
核物理学
氘
各向异性
星星
量子力学
生物
复合材料
材料科学
渔业
出处
期刊:Chinese Physics C
[IOP Publishing]
日期:2014-08-01
卷期号:38 (9): 090001-090001
被引量:5601
标识
DOI:10.1088/1674-1137/38/9/090001
摘要
A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial abundances of deuterium and helium-4 is consistent with the independent determination of $\eta$ from observations of anisotropies in the cosmic microwave background. However the primordial abundance of lithium-7 inferred from observations is significantly below its expected value. Taking systematic uncertainties in the abundance estimates into account, there is overall concordance in the range $\eta = (5.7-6.7)\times 10^{-10}$ at 95% CL (corresponding to a cosmological baryon density $\Omega_B h^2 = 0.021 - 0.025$). The D and He-4 abundances, when combined with the CMB determination of $\eta$, provide the bound $N_\nu=3.28 \pm 0.28$ on the effective number of neutrino species. Other constraints on new physics are discussed briefly.
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