arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.16692astro-ph.CO
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晚期宇宙的哈勃常数和声视界

Hubble constant and sound horizon from the late-time Universe

Xue Zhang, Qing-Guo Huang

摘要:

我们利用低红移数据测量了近代宇宙的膨胀率和重子声振荡(BAO)的刻度。BAO依赖于校准标度,即,拖曳期$r_d$结束时的声视界,这通常会对普朗克卫星的宇宙微波背景(CMB)测量产生影响。为了对$H_0$进行真正独立的测量,我们将$r_d$完全免费,并使用BAO数据集与31个观测数据$H(z)$,GW 170817和Ia型超新星的Pantheon样本相结合。在$Λ$ CDM模型中,我们得到了$H_0=68.63^{+1.75}_{-1.77}$ km s $^{-1}$ Mpc $^{-1}$,$r_d=146.85^{+3.29}_{-3.77}$ Mpc.对于$H(z)$的两个模型无关重建,我们得到了三次展开的$H_0=68.02\pm1.82$ km s $^{-1}$ Mpc $^{-1}$,$r_d=148.18^{+3.36}_{-3.78}$ Mpc和多项式展开的$H_0=68.58\pm1.76$ km s $^{-1}$ Mpc $^{-1}$,$r_d=148.02^{+3.63}_{-3.60}$ Mpc.哈勃常数$H_0$和声音视界$r_d$的值与假设平坦$Λ$ CDM模型的普朗克CMB数据得出的估计一致,但$H_0$分别与SH0 ES 2019处于$2.4\sim2.6$ $σ$张力中。

英文摘要:

We measure the expansion rate of the recent Universe and the calibration scale of the baryon acoustic oscillation (BAO) from low-redshift data. BAO relies on the calibration scale, i.e., the sound horizon at the end of drag epoch $r_d$, which often imposes a prior of the cosmic microwave background (CMB) measurement from the Planck satellite. In order to make really independent measurements of $H_0$, we leave $r_d$ completely free and use the BAO data sets combined with the 31 observational $H(z)$ data, GW170817 and Pantheon sample of Type Ia supernovae. In $Λ$CDM model, we get $H_0=68.63^{+1.75}_{-1.77}$ km s$^{-1}$ Mpc$^{-1}$, $r_d=146.85^{+3.29}_{-3.77}$ Mpc. For the two model-independent reconstructions of $H(z)$, we obtain $H_0=68.02\pm1.82$ km s$^{-1}$ Mpc$^{-1}$, $r_d=148.18^{+3.36}_{-3.78}$ Mpc in the cubic expansion, and $H_0=68.58\pm1.76$ km s$^{-1}$ Mpc$^{-1}$, $r_d=148.02^{+3.63}_{-3.60}$ Mpc in the polynomial expansion. The values of Hubble constant $H_0$ and sound horizon $r_d$ are consistent with the estimate derived from the Planck CMB data assuming a flat $Λ$CDM model, but $H_0$ is in $2.4\sim2.6$ $σ$ tension with SH0ES 2019, respectively.

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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