Which spectral distortions does ΛCDM actually predict
Which spectral distortions does ΛCDM actually predict
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DOI：
10.1093/mnras/stw945
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发表时间：
2016-03
影响因子：
4.8
通讯作者：
J. Chluba
中科院分区：
文献类型：
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作者：
J. Chluba
不断完善的宇宙学测量已经建立了ΛCDM和谐模型，其中关键的宇宙学参数今天被确定到百分之一级的精度。这使我们能够对宇宙微波背景辐射（CMB）的光谱扭曲做出明确的预测，这些光谱扭曲是由早期宇宙中发生的各种过程造成的。在这里，我们总结了所有保证CMB失真，并评估其总的不确定性在ΛCDM。我们还比较了近似它们的简单方法，突出了一些微妙的方面，当涉及到解释未来的失真测量。在简化的假设下，我们简要研究了PIXIE类实验如何测量主要失真参数（即μ和y）。下一代CMB光谱仪有望以极高的显著性检测由再电离和结构形成引起的失真。它们还将能够通过相关的μ失真来限制小尺度功率谱，从而改善对谱指数运行的限制。来自复合时代的扭曲，物质相对于CMB的绝热冷却和暗物质湮灭需要比PIXIE更高的灵敏度。关键的下一步是改进前景和工具方面的建模，我们在这里简要讨论。
Ever refined cosmological measurements have established the ΛCDM concordance model, with the key cosmological parameters being determined to per cent-level precision today. This allows us to make explicit predictions for the spectral distortions of the cosmic microwave background (CMB) created by various processes occurring in the early Universe. Here, we summarize all guaranteed CMB distortions and assess their total uncertainty within ΛCDM. We also compare simple methods for approximating them, highlighting some of the subtle aspects when it comes to interpreting future distortion measurements. Under simplified assumptions, we briefly study how well a PIXIE-like experiment may measure the main distortion parameters (i.e. μ and y). Next-generation CMB spectrometers are expected to detect the distortion caused by reionization and structure formation at extremely high significance. They will also be able to constrain the small-scale power spectrum through the associated μ-distortion, improving limits on running of the spectral index. Distortions from the recombination era, adiabatic cooling of matter relative to the CMB and dark matter annihilation require a higher sensitivity than PIXIE in its current design. The crucial next step is an improved modelling of foregrounds and instrumental aspects, as we briefly discuss here.