论文标题
快速无线电爆发对氦气丰度的限制
Constraints on the Helium Abundance from Fast Radio Bursts
论文作者
论文摘要
通过分散度量（DM）和红移之间的关系，快速无线电爆发（FRB）被认为是非常有前途的宇宙学探针。在本文中，我们试图使用FRB的DM-Z关系来研究宇宙中的氦气丰度（$ y _ {\ rm he} $）。首先，我们在研究中使用了17个带有已知红移的FRB。由于它们的低红移以及$ y _ {\ rm He} $和$ω_bh^2 $之间的强烈退化，因此该目录无法对氦气丰度提供良好的限制。然后，我们用[0，\，1.5] $中的$ z \模拟了500个低红移FRB模拟数据，以预测$ y _ {\ rm He} $的约束能力。为了打破$ y _ {\ rm he} $和$ω_bh^2 $之间的退化，我们介绍了普朗克测量$（r，l_a，l_a，ω_bh^2）$的偏移参数，作为先前的，$ω_bh^2 $代表$ω_bh^2 $代表BAINEON密度参数和$ $ $ $ $ RA的$ r_ $ r $ raa $ r $ ra $ ra $ r $ raa ya $ r $ raa ya $ r $ ra $ ra $ ra $ r $ raa yaa重组时的声音范围的比例。我们获得了氦气丰度的标准偏差：$σ（{y _ {\ rm He}}}）= 0.025 $。最后，我们考虑了$ [0，\，3] $的红移分布的2000个较高的红移FRB数据，发现$ y _ {\ rm he} $的约束功率将提高2次以上，$σ（{y _ _ _ _ {\ rm He}}} = 0.011 $，这表明了hel frb frb的数据，并可以提供高度redshift的数据。希望从平方公里阵列中具有高红移的大型FRB样品可以在不久的将来提供氦气丰度的高精度测量。
Through the relationship between dispersion measures (DM) and redshifts, fast radio bursts (FRBs) are considered to be very promising cosmological probes. In this paper, we attempted to use the DM-z relationship of FRBs to study the helium abundance ($Y_{\rm He}$) in the universe. First, we used 17 current FRBs with known redshifts for our study. Due to their low redshifts and the strong degeneracy between $Y_{\rm He}$ and $Ω_bh^2$, however, this catalog could not provide a good constraint on the helium abundance. Then, we simulated 500 low redshift FRB mock data with $z\in[0,\,1.5]$ to forecast the constraining ability on $Y_{\rm He}$. In order to break the degeneracy between $Y_{\rm He}$ and $Ω_bh^2$ further, we introduced the shift parameters of the Planck measurement $(R,l_A,Ω_bh^2)$ as a prior, where $Ω_bh^2$ represents the baryon density parameter, and $R$ and $l_A$ correspond to the scaled distance to recombination and the angular scale of the sound horizon at recombination, respectively. We obtained the standard deviation for the helium abundance: $σ({Y_{\rm He}}) = 0.025$. Finally, we considered 2000 higher redshift FRB data with the redshift distribution of $[0,\,3]$ and found that the constraining power for $Y_{\rm He}$ would be improved by more than 2 times, $σ({Y_{\rm He}}) = 0.011$, which indicates that the FRB data with high redshift can provide a better constraint on the helium abundance. Hopefully, large FRB samples with high redshift from the Square Kilometre Array can provide high-precision measurements of the helium abundance in the near future.
