Cosmology with standard sirens at cosmic noon
Cosmology with standard sirens at cosmic noon
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DOI：
10.1103/physrevd.104.043507
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发表时间：
2021-03
影响因子：
5
通讯作者：
C. Ye;M. Fishbach
中科院分区：
文献类型：
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作者：
C. Ye;M. Fishbach
来自黑洞和中子星合并的引力波(GW)直接测量到合并的光度距离，当与源红移的独立测量结合在一起时，提供了一个新的宇宙学探测器。计划中的下一代地面GW探测器，爱因斯坦望远镜和宇宙探索者，将探测数万颗双星中子星(BNSS)，距离宇宙距离(z>；2)，超过恒星形成率(SFR)的峰值，或“宇宙正午”。在这样的距离下，要通过观测电磁(EM)对应物或在星系星表上进行统计边缘化来测量源的红移将是一项挑战。在没有EM对应星表或星系星表的情况下，丁等人。[1]证明了合并红移分布的理论先验可以用来推断wCDM宇宙学中的参数。我们认为，在BNS的情况下，红移分布将通过对短伽马射线暴(GRB)、千新星和已知的BNS宿主星系的独立观测来测量。特别是，峰值红移将提供一个清晰的特征来与GW源分布的峰值距离进行比较，并揭示潜在的红移-距离关系。结果表明，除了测量背景宇宙学外，该方法还可以抑制暗能量对修正的GW传播的影响。作为一个简单的例子，我们考虑了BNS率是已知遵循SFR的先验的情况。如果SFR是完全已知的，O(10,000)个事件(预计在宇宙探测器观测的一年内)将产生在扁平Ω清洁发展机制模型中的组合H0ΛM的不到10%的测量值。同时，将H0和ΩM固定为独立推断的值，该方法可以对wCDM模型中的暗能量状态方程参数w进行5%的测量。固定背景宇宙论，而不是探测修正的GW传播，普朗克质量参数Cm的运行可以测量到±0.02。虽然在现实中，合并率的红移演化将是不确定的，但关于峰值红移的先验知识将为标准的警报器分析提供有价值的信息。
Gravitational waves (GWs) from merging black holes and neutron stars directly measure the luminosity distance to the merger, which, when combined with an independent measurement of the source’s redshift, provides a novel probe of cosmology. The proposed next generation of groundbased GW detectors, Einstein Telescope and Cosmic Explorer, will detect tens of thousands of binary neutron stars (BNSs) out to cosmological distances (z > 2), beyond the peak of the star formation rate (SFR), or “cosmic noon.” At these distances, it will be challenging to measure the sources’ redshifts by observing electromagnetic (EM) counterparts or statistically marginalizing over a galaxy catalog. In the absence of an EM counterpart or galaxy catalog, Ding et al. [1] showed that theoretical priors on the merger redshift distribution can be used to infer parameters in a wCDM cosmology. We argue that in the BNS case, the redshift distribution will be measured by independent observations of short gamma ray bursts (GRBs), kilonovae, and known BNS host galaxies. In particular, the peak redshift will provide a clear feature to compare against the peak distance of the GW source distribution and reveal the underlying redshift-distance relation. We show that, in addition to measuring the background cosmology, this method can constrain the effects of dark energy on modified GW propagation. As a simple example, we consider the case in which the BNS rate is a priori known to follow the SFR. If the SFR is perfectly known, O(10, 000) events (to be expected within a year of observation with Cosmic Explorer) would yield a sub-tenth percent measurement of the combination H 0 ΩM in a flat ΛCDM model. Meanwhile, fixing H0 and ΩM to independently-inferred values, this method may enable a 5% measurement of the dark energy equation of state parameter w in a wCDM model. Fixing the background cosmology and instead probing modified GW propagation, the running of the Planck mass parameter cM may be measured to ±0.02. Although realistically, the redshift evolution of the merger rate will be uncertain, prior knowledge of the peak redshift will provide valuable information for standard siren analyses.