论文标题
来自全局21cm信号和外层次伽马射线背景的原始黑洞的丰度
The abundance of primordial black holes from the global 21cm signal and extragalactic gamma-ray background
论文作者
论文摘要
早期宇宙中形成的原始黑洞（PBHS）可以由于重力而引起的暗物质颗粒并形成超型Minihalos（UCMHS）。理论研究和模拟表明，UCMHS中暗物质的密度曲线的形式为$ρ（r）\ sim r^{ - 2.25} $。与流行的暗物质光环模型相比，例如NFW模型，暗物质歼灭率在UCMHS中较大。考虑到暗物质歼灭，UCMHS中有一个最大核心密度$ρ_ {\ rm max} $，该$已在红移上独立处理。在这项工作中，我们指出$ρ_ {\ rm max} $取决于UCMHS中的红移和暗物质歼灭率也随时间而变化。由于暗物质歼灭，我们重新投资了UCMHS的$γ$ - ray通量，并专注于它们对外层次伽马射线背景（EGB）的贡献。利用FERMI的EGB数据，得出了PBH的限制，$ω_ {\ rm PBH，EGB} \ Lessim 2 \ times 10^{ - 8} $。通过边缘实验对全球21cm信号的最新观察，我们调查了UCMHS中暗物质歼灭的影响，并得出了对PBHS的丰度的约束，$ω_{\ rm PBH，21cm} \ 21cm} \ 21cm} \ 21cm} \ simsim 2 \ \ times 10^$ 10^^$ 10^ - { - 10}}派生的约束对于$ 10^{ - 6} m _ {\ odot} \ sillssim m _ {\ rm pbh} \ sillesim 10^{3} m _ {\ odot} $有效。
Primordial black holes (PBHs) formed in the early Universe can accret dark matter particles due to gravity and form ultracompact minihalos (UCMHs). The theoretical researches and simulations have shown that the density profile of dark matter in UCMHs is in the form of $ρ(r) \sim r^{-2.25}$. Compared with the popular dark matter halo model, e.g. NFW model, dark matter annihilation rate is larger in UCMHs. Considering dark matter annihilation, there is a maximum core density $ρ_{\rm max}$ in UCMHs which has been treated independent on redshift. While in this work, we point out that $ρ_{\rm max}$ depends on redshift and dark matter annihilation rate in UCMHs also changes with time. We re-investigate the $γ$-ray flux from UCMHs due to dark matter annihilation and focus on their contributions to the extragalactic gamma-ray background (EGB). Utilizing the EGB data of Fermi, the constraints on the abundance of PBHs are derived, $Ω_{\rm PBH,EGB} \lesssim 2\times 10^{-8}$. Motivated by the recent observations of global 21cm signals by the EDGES experiment, we investigate the influences of dark matter annihilation in UCMHs on global 21cm signals and derive the constraints on the abundance of PBHs, $Ω_{\rm PBH,21cm} \lesssim 2\times 10^{-10}$. The derived constraints are valid for mass range of $10^{-6} M_{\odot} \lesssim M_{\rm PBH} \lesssim 10^{3} M_{\odot}$.
