Constraining the spatial curvature with cosmic expansion history in a cosmological model with a non-standard sound horizon
Constraining the spatial curvature with cosmic expansion history in a cosmological model with a non-standard sound horizon
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DOI：
10.1088/1475-7516/2023/07/046
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发表时间：
2022-12
影响因子：
6.4
通讯作者：
Jordan Stevens;Hasti Khoraminezhad;Shun Saito
中科院分区：
文献类型：
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作者：
Jordan Stevens;Hasti Khoraminezhad;Shun Saito
空间曲率是我们目前的宇宙和谐平坦ΛCDM模型中最基本的参数之一。这项工作的目标是调查如何约束的空间曲率的影响的假设上的声音地平线尺度。声视界是宇宙微波背景辐射和重子声振荡中使用标准标尺的一个基本量。作为一个例子，我们研究的曲率约束的轴子早期暗能量（EDE）模型在最近的宇宙学数据集从普朗克，南极望远镜（SPT），和阿塔卡马宇宙学望远镜（ACT），以及BAO数据汇编在斯隆数字巡天数据发布16。我们发现，独立的CMB数据集，EDE模型参数仅受CMB功率谱的精确和一致的平坦的情况下，在以前的工作中，即使与空间曲率。我们还证明了，将CMB与BAO结合起来，即使在EDE模型中降低了声音水平尺度，也能非常有效地约束曲率参数，在边缘化EDE模型参数后，ACT+BAO的情况下，得到Ω K = -0.0058± 0.0031。这个约束与普朗克+BAO在ΛCDM模型中的结果一样具有竞争力，Ω K = -0.0001± 0.0018。
Spatial curvature is one of the most fundamental parameters in our current concordance flat ΛCDM model of the Universe. The goal of this work is to investigate how the constraint on the spatial curvature is affected by an assumption on the sound horizon scale. The sound horizon is an essential quantity to use the standard ruler from the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAOs). As an example, we study the curvature constraint in an axion-like Early Dark Energy (EDE) model in light of recent cosmological datasets from Planck, the South Pole Telescope (SPT), and the Atacama Cosmology Telescope (ACT), as well as BAO data compiled in Sloan Digital Sky Survey Data Release 16. We find that, independent of the CMB datasets, the EDE model parameters are constrained only by the CMB power spectra as precisely and consistently as the flat case in previous work, even with the spatial curvature. We also demonstrate that combining CMB with BAO is extremely powerful to constrain the curvature parameter even with a reduction of the sound-horizon scale in an EDE model, resulting in Ω K = -0.0058± 0.0031 in the case of ACT+BAO after marginalizing over the parameters of the EDE model. This constraint is as competitive as the Planck+BAO result in a ΛCDM model, Ω K = -0.0001± 0.0018.