发表机构
Univ Toulouse; CNES; CNRS; IRAP; Institute of Space Sciences (ICE, CSIC); Institut d’Estudis Espacials de Catalunya (IEEC)（图卢兹大学; 法国国家空间研究中心; 法国国家科学研究中心; 天体物理与行星科学研究所; 空间科学研究所（ICE, CSIC）; 加泰罗尼亚空间研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文针对物质密度参数$Ω_{\rm m}$，首次将宇宙学参数推断的影响拆分为几何、增长、早期宇宙三个领域，利用多组观测数据开展分析，发现几何与早期宇宙领域强相关，且两者差值达2σ偏差。
AI 中文摘要
尽管$\boldsymbol{\rm Λ}$冷暗物质（$\boldsymbol{\rm Λ}$CDM）模型能成功复现众多宇宙学探针的测量结果，但近来出现了一些偏差，因此有必要检验标准宇宙学模型的一致性，一项重要的压力测试是区分不同宇宙学领域对参数推断的影响。本文将三个领域分开处理：几何领域涉及膨胀与曲率演化，增长领域主导结构形成，早期宇宙领域影响复合之前的物理过程。此前的分析仅拆分了几何与增长领域，而本文还单独考虑早期宇宙的影响，利用多种宇宙学观测数据对现今物质密度参数$\boldsymbol{Ω_{\rm m}}$进行该拆分。所用数据包括：暗能量巡天（DES）的星系成团与弱引力透镜统计（3x2pt）、普朗克（Planck）的宇宙微波背景（CMB）数据、暗能量光谱仪（DESI）的光谱重子声学振荡（BAO）、Pantheon+的Ia型超新星（SNe Ia）样本，以及多组星系巡天的红移空间畸变（RSD）。对每类探针，本文引入了将其拆分为上述三个领域的唯象方法。研究表明，物质密度的几何领域与早期宇宙领域存在强相关性，但增长领域与另外两个领域无强相关性；各领域在后验分布中均相容，不过几何领域与早期宇宙领域的差值$\boldsymbol{ΔΩ_{\rm m}^{\rm geo,early}}$与0的偏差达到2σ。
英文摘要
While the $Λ$ cold dark matter ($Λ$CDM) model can successfully reproduce the measurements of many cosmological probes, some discrepancies have recently emerged. It is therefore necessary to test the standard cosmological model for consistency. An important stress test is to separate the effect of different cosmological regimes on the parameter inference. We treat three regimes separately here: geometry, growth, and the early Universe. The geometric regime concerns the expansion and curvature history, the growth regime governs structure formation, and the early-universe regime affects physics prior to recombination. Previous analyses have performed the split between geometry and growth, whereas we also consider the influence of the early Universe separately. We performed this split for the present-day matter density parameter $Ω_{\rm m}$ using multiple cosmological observables. The data we used are galaxy clustering and weak-lensing statistics (3x2pt) from the Dark Energy Survey, cosmic microwave background data from Planck, baryon acoustic oscillations from the Dark Energy Spectroscopic Instrument, type Ia supernovae samples from Pantheon+, and redshift-space distortions from a collection of galaxy surveys. For each of these probes, we introduced a phenomenological split into these three regimes. The correlation between the geometric and the early regime for the matter density is strong, but that between the growth regime and the others is not. All regimes are compatible in the posterior distribution, but the difference between the geometry and the early regimes, $ΔΩ_{\rm m}^{\rm geo,early}$, has a 2$σ$ discrepancy with 0.
Comments14 pages including references, 15 figures, accepted for publication in A&A
