论文标题

CMB温度,空间曲率和膨胀速率参数的相互作用

Interplay of CMB Temperature, Space Curvature, and Expansion Rate Parameters

论文作者

Shimon, Meir, Rephaeli, Yoel

论文摘要

从{\ it local}的测量值推断,宇宙微波背景(CMB)温度肯定是最精确测量的宇宙学参数,它是黑体光谱的{\ it local}测量值,即在$ \ sim 4700 $中的精确精度。另一方面,当前精度允许从CMB功率谱,星系相关和镜头,超新星的光度距离测量以及其他宇宙学探针中推断出$ \ sim 1 \%$级别的其他基本宇宙学参数。标准宇宙学模型的基本一致性检查是重组时$ t $的独立推断。在这项工作中,我们首先使用了最新的Planck数据,并补充了Dark Energy Survey(DES),Baryon声学振荡(BAO)数据和Pantheon Snia目录的第一年数据,以在$ \ sim 1 \%$ $精度级别提取$ t $。然后,我们探索$ t $,hubble参数,$ h_ {0} $与全局空间曲率参数之间的相关性。我们的参数估计表明,在$ h_ {0} $上从SH0ES实验中施加本地约束会导致重新组合从本地推断出的$ t $重组时出现的统计偏好。但是,如果在$ h_ {0} $放松的本地限制下,仅在此分析中发现了对本地和宇宙学估计之间的张力的中等证据。所有其他数据集合组合,包括带有BAO,SNIA或两者兼而有之的CMB,即使在$ H_ {0} $上存在局部约束的情况下,也不利于添加新的自由温度参数。限于Planck数据集的分析表明,如果空间在全球范围内,则重组时的重组温度高于$ \ gtrsim 95 \%$置信度的预期。

The cosmic microwave background (CMB) temperature, $T$, surely the most precisely measured cosmological parameter, has been inferred from {\it local} measurements of the blackbody spectrum to an exquisite precision of 1 part in $\sim 4700$. On the other hand, current precision allows inference of other basic cosmological parameters at the $\sim 1\%$ level from CMB power spectra, galaxy correlation and lensing, luminosity distance measurements of supernovae, as well as other cosmological probes. A basic consistency check of the standard cosmological model is an independent inference of $T$ at recombination. In this work we first use the recent Planck data, supplemented by either the first year data release of the dark energy survey (DES), baryon acoustic oscillations (BAO) data, and the Pantheon SNIa catalog, to extract $T$ at the $\sim 1\%$ precision level. We then explore correlations between $T$, the Hubble parameter, $H_{0}$, and the global spatial curvature parameter, $Ω_{k}$. Our parameter estimation indicates that imposing the local constraint from the SH0ES experiment on $H_{0}$ results in significant statistical preference for departure at recombination from the locally inferred $T$. However, only moderate evidence is found in this analysis for tension between local and cosmological estimates of $T$, if the local constraint on $H_{0}$ is relaxed. All other dataset combinations that include the CMB with either BAO, SNIa, or both, disfavor the addition of a new free temperature parameter even in the presence of the local constraint on $H_{0}$. Analysis limited to the Planck dataset suggests the temperature at recombination was higher than expected at recombination at the $\gtrsim 95\%$ confidence level if space is globally flat.

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