论文标题
瑞利各向异性的原始信息内容
The primordial information content of Rayleigh Anisotropies
论文作者
论文摘要
宇宙微波背景(CMB)中的各向异性主要是通过游离电子对光子散射产生的。在重组周围,汤姆森散射概率迅速降低,因为自由电子与质子结合以形成中性氢,cmb光子可以通过瑞利散射散射。与汤姆森散射不同,瑞利散射是频率依赖性的,导致各向异性具有不同的光谱依赖性。不幸的是,随着中性宇宙的膨胀,瑞利散射效率迅速降低,结果只有一小部分光子被中性氢散射。尽管效果非常小,但未来的CMB任务具有更高的灵敏度和提高的频率覆盖率,可以测量瑞利散射信号。瑞利各向异性的不相关组成部分包含有关原始扰动的独特信息,这些信息可能会利用,以扩大我们对早期宇宙的了解。在本文中,我们探讨了瑞利散射各向异性的测量是否可用于限制原始非高斯(NG)并检查WMAP和\ textit {planck}卫星的异常提示。我们表明,额外的雷利信息有可能将原始ng限制提高$ 30 \%$或更多。非局部类型的原始双光谱从这些其他散射中受益最大,我们将其归因于瑞利各向异性的不同规模依赖性。不幸的是,这种不同的尺度意味着瑞利测量值不能用于限制大尺度上的异常或特征。另一方面,可以通过添加瑞利测量值来改善可能会持续到较小尺度的异常,例如WMAP和\ textit {planck}中的潜在功率不对称。
Anisotropies in the cosmic microwave background (CMB) are primarily generated by Thomson scattering of photons by free electrons. Around recombination, the Thomson scattering probability quickly diminishes as the free electrons combine with protons to form neutral hydrogen off which CMB photons can scatter through Rayleigh scattering. Unlike Thomson scattering, Rayleigh scattering is frequency dependent resulting in the generation of anisotropies with a different spectral dependence. Unfortunately the Rayleigh scattering efficiency rapidly decreases with the expansion of the neutral universe, with the result that only a small percentage of photons are scattered by neutral hydrogen. Although the effect is very small, future CMB missions with higher sensitivity and improved frequency coverage are poised to measure Rayleigh scattering signal. The uncorrelated component of the Rayleigh anisotropies contains unique information on the primordial perturbations that could potentially be leveraged to expand our knowledge of the early universe. In this paper we explore whether measurements of Rayleigh scattering anisotropies can be used to constrain primordial non-Gaussianity (NG) and examine the hints of anomalies found by WMAP and \textit{Planck} satellites. We show that the additional Rayleigh information has the potential to improve primordial NG constraints by $30\%$, or more. Primordial bispectra that are not of the local type benefit the most from these additional scatterings, which we attribute to the different scale dependence of the Rayleigh anisotropies. Unfortunately this different scaling means that Rayleigh measurements can not be used to constrain anomalies or features on large scales. On the other hand, anomalies that may persist to smaller scales, such as the potential power asymmetry seen in WMAP and \textit{Planck}, could be improved by the addition of Rayleigh measurements.