论文标题
测量宇宙低密度区域的综合sachs-wolfe效应
Measuring the integrated Sachs-Wolfe effect from the low-density regions of the universe
论文作者
论文摘要
综合的sachs-wolfe(ISW)效应是由宇宙学重力潜力的衰减引起的,因此是对暗能量的独特探针。但是,其可靠的检测仍然存在问题。存在不同数据集,不同大规模结构(LSS)示踪剂以及数据与$λ$ CDM理论预测之间的各种紧张关系。我们通过将CMB相关的CMB和LSS通过“低密度位置”(LDP,\ citet {2019apj ... 874 .... 7d})提出了一种新的ISW测量方法。它隔离了宇宙低密度区域产生的ISW效应,但对与空隙相关的选择效应不敏感。我们将其应用于DESI传统成像调查的DR8 Galaxy目录,并以$ z \ leq 0.6 $ $ \ sim $ \ sim $ 20000 $ deg^2 $ Sky Coverage获取LDP。然后,我们与普朗克温度图相互关联,并以$3.2σ$检测ISW效果。我们进一步将测量与一致性$ CDM宇宙学的数值模拟进行了比较,并找到ISW振幅参数$ a_ {isw} = 1.14 \ pm0.38 $当我们采用LDP定义radius $ r_s = 3^{'} $时,与标准$ cos $ cosm cosm cosm cosm cosm cos cosm cos cosm cosmigant与$λ$ CDM Cosmology的该协议符合我们研究的所有星系样本和$ R_S $。此外,S/N与Galaxy ISW测量值相当。这些结果证明了LDP方法是现有ISW测量方法的竞争替代方法,并为现有紧张局势提供了独立的检查。
The integrated Sachs-Wolfe (ISW) effect is caused by the decay of cosmological gravitational potential, and is therefore a unique probe of dark energy. However, its robust detection is still problematic. Various tensions between different data sets, different large scale structure (LSS) tracers, and between data and the $Λ$CDM theory prediction, exist. We propose a novel method of ISW measurement by cross correlating CMB and the LSS traced by "low-density-position" (LDP, \citet{2019ApJ...874....7D}). It isolates the ISW effect generated by low-density regions of the universe, but insensitive to selection effects associated with voids. We apply it to the DR8 galaxy catalogue of the DESI Legacy imaging surveys, and obtain the LDPs at $z\leq 0.6$ over $\sim$ 20000 $deg^2$ sky coverage. We then cross correlate with the Planck temperature map, and detect the ISW effect at $3.2σ$. We further compare the measurement with numerical simulations of the concordance $Λ$CDM cosmology, and find the ISW amplitude parameter $A_{ISW}=1.14\pm0.38$ when we adopt a LDP definition radius $R_s=3^{'}$, fully consistent with the prediction of the standard $Λ$CDM cosmology ($A_{ISW}=1$). This agreement with $Λ$CDM cosmology holds for all the galaxy samples and $R_s$ that we have investigated. Furthermore, the S/N is comparable to that of galaxy ISW measurement. These results demonstrate the LDP method as a competitive alternative to existing ISW measurement methods, and provide independent checks to existing tensions.