KiDS-1000 cosmology: Constraints from density split statistics
KiDS-1000 cosmology: Constraints from density split statistics
复制标题
KiDS-1000 宇宙学：密度分裂统计的约束
DOI：
10.1051/0004-6361/202244673
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发表时间：
2023
影响因子：
6.5
通讯作者：
Burger P
中科院分区：
文献类型：
--
作者：
Burger P
背景超越两点函数的弱透镜和聚类统计可以捕获物质密度场的非高斯信息，从而相对于基于相关函数和功率谱的主流方法改善对宇宙学参数的约束。目的本文提出了基于密度分裂统计的千度巡天第四次数据发布的宇宙学分析，密度分裂统计测量了根据前景密度分类的区域周围的平均剪切剖面。后者是由明亮的星系样本构建的，我们将其进一步分成红色和蓝色样本，使我们能够探测它们各自与底层暗物质密度的联系。方法我们使用了最先进的密度分裂统计模型，并验证了其针对注入了已知系统效应（例如内在星系排列和重子反馈）的模拟数据的鲁棒性。结果在边缘化光度红移不确定性和残余剪切校准偏差后，我们测量了完整的 KiDS-bright 样本的结构生长参数，该参数具有竞争性和与两点宇宙剪切结果一致，物质密度Ωm= 0.27 ± 0.02，恒定星系偏差b= 1.37 ± 0.10。
ContextWeak lensing and clustering statistics beyond two-point functions can capture non-Gaussian information about the matter density field, thereby improving the constraints on cosmological parameters relative to the mainstream methods based on correlation functions and power spectra.AimsThis paper presents a cosmological analysis of the fourth data release of the Kilo Degree Survey based on the density split statistics, which measures the mean shear profiles around regions classified according to foreground densities. The latter is constructed from a bright galaxy sample, which we further split into red and blue samples, allowing us to probe their respective connection to the underlying dark matter density.MethodsWe used the state-of-the-art model of the density splitting statistics and validated its robustness against mock data infused with known systematic effects such as intrinsic galaxy alignment and baryonic feedback.ResultsAfter marginalising over the photometric redshift uncertainty and the residual shear calibration bias, we measured for the full KiDS-bright sample a structure growth parameter of that is competitive and consistent with two-point cosmic shear results, a matter density of Ωm= 0.27 ± 0.02, and a constant galaxy bias ofb= 1.37 ± 0.10.