Constraining isocurvature perturbations with the 21 cm emission from minihaloes
Constraining isocurvature perturbations with the 21 cm emission from minihaloes
复制标题
用迷你晕的 21 cm 发射约束等曲率扰动
DOI：
10.1093/mnras/stu059
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发表时间：
2013
影响因子：
4.8
通讯作者：
S. Chongchitnan
中科院分区：
文献类型：
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作者：
Yoshitaka Takeuchi;S. Chongchitnan
我们研究了等曲率扰动对高红移迷你晕 (MH) 21 厘米辐射的影响，并使用下一代射电望远镜（例如平方公里阵列）检查等曲率振幅和功率谱的约束。我们发现，在 MH 的 21 cm 发射中观察等曲率印记是有现实前景的，但前提是等曲率光谱指数接近 3（即光谱为蓝色）。当等曲率分数增加超过绝热分量的 10% 时，我们观察到小质量 MH 的 21 cm 波动意外下降，这可以通过将小 MH 合并到较大的晕中来解释。我们进行了详细的费舍尔矩阵分析，得出的结论是，未来宇宙微波背景和21cm实验（例如CMBPol和快速傅里叶变换望远镜）的结合对于约束等曲率参数来说是理想的，但将无法区分冷暗物质和重子类型的等曲率扰动，除非等曲率分数很大并且光谱是蓝色的。
We investigate the effects of isocurvature perturbations on the 21 cm radiation from minihaloes (MHs) at high redshifts and examine constraints on the isocurvature amplitude and power spectrum using the next generation of radio telescopes such as the Square Kilometre Array. We find that there is a realistic prospect of observing the isocurvature imprints in the 21 cm emission from MHs, but only if the isocurvature spectral index is close to 3 (i.e. the spectrum is blue). When the isocurvature fraction increases beyond ∼10 per cent of the adiabatic component, we observe an unexpected decline in the 21 cm fluctuations from small-mass MHs, which can be explained by the incorporation small MHs into larger haloes. We perform a detailed Fisher-matrix analysis and conclude that the combination of future cosmic microwave background and 21 cm experiments (such as CMBPol and the Fast Fourier Transform Telescope) is ideal in constraining the isocurvature parameters, but will stop short of distinguishing between cold dark matter and baryon types of isocurvature perturbations, unless the isocurvature fraction is large and the spectrum is blue.
具有极蓝光谱的轴子等曲率波动
DOI：
--
发表时间：
2009
期刊：
Phys.Rev. D80
影响因子：
--
作者：
S. Kasuya;M. Kawasaki
通讯作者：
M. Kawasaki
非轴对称扰动对轮廓形成的影响
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
森崎友宏;et al.
通讯作者：
et al.