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arXiv 2406.04830astro-ph.CO
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来自21cm强度映射中重子声学振荡的宇宙学预测

Cosmological Forecasts from the Baryon Acoustic Oscillations in 21cm Intensity Mapping

Benjamin Ostergaard, André Alencar da Costa, Yu Sang

AI总结:

本文利用模板方法从21cm强度映射中提取BAO信号,结合Fisher矩阵与Planck CMB数据,预测了哈勃常数和暗能量参数的约束,并比较了完整APS与仅BAO的约束强度。

摘要:

在这项工作中,我们使用模板方法从21cm中性氢强度图中提取与重子声学振荡(BAO)信号相关的尺度。随后,我们利用Fisher矩阵分析预测宇宙学参数标准差的约束。为测试该方法,我们选用了BINGO望远镜的巡天配置。我们估算了从21cm角功率谱(APS)中提取的BAO位移参数$\alpha$的约束。此外,我们将这些结果转化为对最终宇宙学参数的约束。由于仅凭BAO数据只能约束哈勃常数与声学视界的乘积$H_0r_s$,变量间的简并意味着我们无法仅用BAO数据获得有效的约束。我们通过将21cm强度映射BAO结果与普朗克卫星获得的宇宙微波背景(CMB)协方差相结合来打破这些简并。特别地,我们发现这种组合能获得的最佳预测是对哈勃参数标准差$\sigma_h$和暗能量参数标准差$\sigma_{w_0}$与$\sigma_{w_a}$的约束。在$\Lambda$CDM模型中,我们得到$\sigma_h = 0.0055\\;(0.8\\%)$。对于$w$CDM模型,我们得到$\sigma_h = 0.020\\;(2.9\\%)$和$\sigma_{w_0} = 0.075\\;(7.5\\%)$。在CPL参数化中,我们得到$\sigma_h = 0.029\\;(4.4\\%)$,$\sigma_{w_0} = 0.40\\;(40\\%)$,以及$\sigma_{w_a} = 1.7$。最后,我们观察到使用完整APS比仅使用BAO能提供更强的约束,但前者更容易受到系统效应的影响。

英文摘要:

In this work we use a template method to extract the scale associated with the Baryon Acoustic Oscillation (BAO) signal in 21cm neutral hydrogen intensity maps. We then forecast the constraints on the standard deviations of cosmological parameters using a Fisher matrix analysis. In order to test this method, we choose the survey configuration for the BINGO telescope. We then estimate the constraints on the BAO shift parameter $α$, which we extract from the 21cm angular power spectrum (APS). In addition, we translate those results into constraints on the final cosmological parameters. As BAO data alone can only constrain the product of the Hubble constant and the sound horizon $H_0r_s$, degeneracies between the variables mean that we can't get useful constraints with BAO data alone. We break these degeneracies by combining the 21cm intensity mapping BAO results with the Cosmic Microwave Background (CMB) covariances obtained by the Planck satellite. In particular, we find that the best forecasts we can get with this combination are on the standard deviations of the Hubble parameter $σ_h$, and the dark energy parameters $σ_{w_0}$ and $σ_{w_a}$. We find $σ_h = 0.0055\;(0.8\%)$ in the $Λ$CDM model. For the $w$CDM model, we find $σ_h = 0.020\;(2.9\%)$ and $σ_{w_0} = 0.075\;(7.5\%)$. In the CPL parameterization, we find $σ_h = 0.029\;(4.4\%)$, $σ_{w_0} = 0.40\;(40\%)$, and $σ_{w_a} = 1.7$. Finally, we observe that using the full APS provides stronger constraints than the BAO only, however, it is more susceptible to systematic effects.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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