$\nu\Lambda$CDM: Neutrinos help reconcile Planck with the Local Universe
$\nu\Lambda$CDM: Neutrinos help reconcile Planck with the Local Universe
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DOI：
10.1103/physrevlett.112.051302
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
Mark Wyman;D. Rudd;R. A. Vanderveld;Wayne Hu
中科院分区：
文献类型：
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作者：
Mark Wyman;D. Rudd;R. A. Vanderveld;Wayne Hu
如果我们把自己限制在标准的六参数平坦ΛCDM模型中，那么目前对低红移和高红移宇宙的测量就会处于紧张状态。这种紧张关系有两个部分。首先，普朗克卫星的数据表明，物质扰动的标准化程度高于星系团的局部测量。第二，从局部距离位移测量得出的宇宙膨胀率H 0，明显高于使用星系巡天中的声学尺度和普朗克数据作为标准标尺推断的宇宙膨胀率。添加一个不育中微子物种改变了声学尺度，使两者一致;同时，增加质量的活动中微子或不育中微子可以抑制结构的增长，使集群数据更好地协调。对于我们的基准数据集组合，具有集群的统计误差，具有大质量无菌中微子的模型显示了3.5σ的非零质量证据，并且更强烈地拒绝了最小模型。一个有大量活动中微子和一个无质量的惰性中微子的模型同样是首选。一个eV尺度的无菌中微子质量--对短基线和反应堆异常感兴趣--完全在允许的范围内。我们警告说，1）任何数据集中未知的天体物理系统误差都可能削弱这一结论，但它们需要数倍于已知误差才能完全消除紧张; 2）我们发现的结果与不包括星团测量的分析有一些差异; 3）即使包括新的中微子物理学，数据集之间仍然存在一些紧张。
Current measurements of the low and high redshift Universe are in tension if we restrict ourselves to the standard six parameter model of flat ΛCDM. This tension has two parts. First, the Planck satellite data suggest a higher normalization of matter perturbations than local measurements of galaxy clusters. Second, the expansion rate of the Universe today, H0, derived from local distanceredshift measurements is significantly higher than that inferred using the acoustic scale in galaxy surveys and the Planck data as a standard ruler. The addition of a sterile neutrino species changes the acoustic scale and brings the two into agreement; meanwhile, adding mass to the active neutrinos or to a sterile neutrino can suppress the growth of structure, bringing the cluster data into better concordance as well. For our fiducial dataset combination, with statistical errors for clusters, a model with a massive sterile neutrino shows 3.5σ evidence for a non-zero mass and an even stronger rejection of the minimal model. A model with massive active neutrinos and a massless sterile neutrino is similarly preferred. An eV-scale sterile neutrino mass – of interest for short baseline and reactor anomalies – is well within the allowed range. We caution that 1) unknown astrophysical systematic errors in any of the data sets could weaken this conclusion, but they would need to be several times the known errors to eliminate the tensions entirely; 2) the results we find are at some variance with analyses that do not include cluster measurements; and 3) some tension remains among the datasets even when new neutrino physics is included.