论文标题
宇宙微波背景各向异性的不可避免的斑点电离的烙印
Inevitable imprints of patchy reionization on the cosmic microwave background anisotropy
论文作者
论文摘要
宇宙中第一颗恒星对宇宙中性氢的电离是一个不均匀的过程，可在游离电子密度中产生空间波动。这些波动导致在宇宙微波背景（CMB）等宇宙学探针中可观察到的特征。我们使用持续的光子二数字模拟\ texttt {script}探索电子密度波动对CMB的影响。我们表明，运动学Sunyaev-Zeldovich（KSZ）和$ b $ mmode极化信号的幅度取决于电子空间分布的斑点以及对回离病史的中点和范围的依赖性。在这一发现的激励下，我们为KSZ和$ b $模板极化信号的振幅提供了新的比例关系，这些信号可以捕获由平均光学深度，电离的宽度以及由斑块校正引起的电子密度的空间波动产生的效果。我们表明，KSZ和$ b $ mmode偏振信号的幅度表现出对电离宽度和电源斑块的不同依赖性，因此对这些CMB探针的联合研究将能够破坏退化。通过将外部数据集结合在21 cm测量值中，可以通过直接探索离子化区域的大小来进一步提高堕落性。
Reionization of the cosmic neutral hydrogen by the first stars in the Universe is an inhomogeneous process which produces spatial fluctuations in free electron density. These fluctuations lead to observable signatures in cosmological probes like the cosmic microwave background (CMB). We explore the effect of the electron density fluctuations on CMB using photon-conserving semi-numerical simulations of reionization named \texttt{SCRIPT}. We show that the amplitude of the kinematic Sunyaev-Zeldovich (kSZ) and $B$-mode polarization signal depends on the patchiness in the spatial distribution of electrons along with the dependence on mid-point and extent of the reionization history. Motivated by this finding, we provide new scaling relations for the amplitude of kSZ and $B$-mode polarization signal which can capture the effects arising from the mean optical depth, width of reionization, and spatial fluctuations in the electron density arising from patchy reionization. We show that the amplitude of the kSZ and $B$-mode polarization signal exhibits different dependency on the width of reionization and the patchiness of reionization, and hence a joint study of these CMB probes will be able to break the degeneracy. By combining external datasets from 21~cm measurements, the degeneracy can be further lifted by directly exploring the sizes of the ionized regions.
