Cosmological parameters from combining the Lyman-α forest with CMB, galaxy clustering and SN constraints
Cosmological parameters from combining the Lyman-α forest with CMB, galaxy clustering and SN constraints
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DOI：
10.1088/1475-7516/2006/10/014
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发表时间：
2006-04
影响因子：
6.4
通讯作者：
U. Seljak;A. Slosar;P. Mcdonald
中科院分区：
文献类型：
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作者：
U. Seljak;A. Slosar;P. Mcdonald
我们将斯隆数字巡天（SDSS）的Ly-α森林功率谱（LYA）与宇宙微波背景（CMB）的高分辨率光谱（包括3年WMAP）、超新星（SN）和星系群集约束相结合，得出了新的宇宙学参数约束。现有的LYA功率谱分析补充了类星体连续体主成分分析得到的平均通量衰减约束，改进了LYA对线性功率的约束。我们发现WMAP3和LYA的功率谱幅值之间在~ 2σ水平上存在一些张力，这部分是通过包含其他观测结果来缓解的：我们发现σ8 = 0.85±0.02，而没有LYA的σ8 = 0.80±0.03。对于斜率，我们得到ns = 0.965±0.012。我们在综合分析中没有发现光谱指数运行的证据，dn/dlnk =−（1.5±1.2）× 10−2，与暴胀一致。对中微子质量总和的限制有了显著的提高：在95% （1.3 (95% c.l)）。假设存在一个热化的第四个中微子，我们发现在95% c.l下ms<0.26 eV，这样的中微子不能解释LSND的结果。在无质量中微子的极限下，我们得到中微子的有效数Nνeff = 5.3−0.6+0.4−1.7+2.1−2.5+3.8，而Nνeff = 3.04仅在2.4 sigma处允许。暗能量状态方程的约束为w =−1.04±0.06。曲率约束为Ωk =−0.003±0.006。宇宙弦在95% c.l.的极限为Gμ<2.3 × 10−7，相关的等曲率模型也受到严格约束。
We combine the Ly-α forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including three-year WMAP, and supernovae (SN) and galaxy clustering constraints to derive new constraints on cosmological parameters. The existing LYA power spectrum analysis is supplemented by constraints on the mean flux decrement derived using a principle component analysis for quasar continua, which improves the LYA constraints on the linear power. We find some tension between the WMAP3 and LYA power spectrum amplitudes, at the ∼2σ level, which is partially alleviated by the inclusion of other observations: we find σ8 = 0.85 ± 0.02 compared to σ8 = 0.80 ± 0.03 without LYA. For the slope, we find ns = 0.965 ± 0.012. We find no evidence for the running of the spectral index in the combined analysis, dn/dlnk = −(1.5 ± 1.2) × 10−2, in agreement with inflation. The limits on the sum of neutrino masses are significantly improved: at 95% (1.3 (95% c.l.). Assuming a thermalized fourth neutrino, we find ms<0.26 eV at 95% c.l. and such a neutrino cannot be an explanation for the LSND results. In the limits of massless neutrinos, we obtain the effective number of neutrinos Nνeff = 5.3−0.6+0.4−1.7+2.1−2.5+3.8 and Nνeff = 3.04 is allowed only at 2.4 sigma. The constraint on the dark energy equation of state is w = −1.04 ± 0.06. The constraint on curvature is Ωk = −0.003 ± 0.006. Cosmic strings limits are Gμ<2.3 × 10−7 at 95% c.l. and correlated isocurvature models are also tightly constrained.