论文标题
宇宙黎明时21厘米信号上的费尔米金和玻色子混合暗物质的烙印
Imprints of fermionic and bosonic mixed dark matter on the 21-cm signal at cosmic dawn
论文作者
论文摘要
在电源之前，来自宇宙黎明时期的21 cm信号由可观察到的有希望的有望获得对暗物质（DM）部门的新见解。在本文中，我们调查了以非冷DM分数（$ f _ {\ rm ncdm} $）和粒子质量（$ m _ {\ rm ncdm} $）为特征的混合（冷 +非冷）暗物质方案的潜力。作为非冷Cold DM物种，我们同时研究了费米子（无菌中微子）和玻色子（超光轴）粒子。我们通过使用宇宙黎明时21-CM信号的卤代模型实现来展示这些方案如何影响全局信号和功率谱。在这项研究之后，我们根据平方公里阵列（SKA）望远镜的逼真的模拟功率谱进行了基于推理的预测研究。假设在Minihaloes中效率低下但非零的星形成（即，质量低于$ 10^8 $ m $ _ {\ odot} $的光环，我们对这两个$ M _ {\ rm ncdm} $} $ _ {\ rm ncdm} $ and $ f _ {\ rm ncdm}的$ M _ {\ rm ncdm} $ {\ rm ncdm} $ ncdm and limits均获得了严格的约束。例如，关于$ f _ {\ rm ncdm} \ sim 1 $的特殊情况，我们找到了$ m _ {\ rm ncdm}> 15 $ kev（热质量）的约束，用于费米子DM和$ M _ {\ rm ncdm}> 2 \ rm ncdm}> 2 \ times10^$ 20} $ 20}。对于统治冷DM的相反情况，我们发现总DM丰度的最多百分之一。所有约束都在95％的置信度下提供。
The 21-cm signal from the epoch of cosmic dawn prior to reionization consists of a promising observable to gain new insights into the dark matter (DM) sector. In this paper, we investigate its potential to constrain mixed (cold + non-cold) dark matter scenarios that are characterised by the non-cold DM fraction ($f_{\rm nCDM}$) and particle mass ($m_{\rm nCDM}$). As non-cold DM species, we investigate both a fermionic (sterile neutrino) and a bosonic (ultra-light axion) particle. We show how these scenarios affect the global signal and the power spectrum using a halo-model implementation of the 21-cm signal at cosmic dawn. Next to this study, we perform an inference-based forecast study based on realistic mock power spectra from the Square Kilometre Array (SKA) telescope. Assuming inefficient, yet non-zero star-formation in minihaloes (i.e. haloes with mass below $10^8$ M$_{\odot}$), we obtain stringent constraints on both $m_{\rm nCDM}$ and $f_{\rm nCDM}$ that go well beyond current limits. Regarding the special case of $f_{\rm nCDM}\sim 1$, for example, we find a constraint of $m_{\rm nCDM}>15$ keV (thermal mass) for fermionic DM and $m_{\rm nCDM}>2\times10^{-20}$ eV for bosonic DM. For the opposite case of dominating cold DM, we find that at most one percent of the total DM abundance can be made of a hot fermionic or bosonic relic. All constraints are provided at the 95 percent confidence level.
