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arXiv 2103.02117astro-ph.COastro-ph.HE
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超新星Ia Pantheon样品中的哈勃常数张力

On the Hubble constant tension in the SNe Ia Pantheon sample

Maria Giovanna Dainotti, Biagio De Simone, Tiziano Schiavone, Giovanni Montani, Enrico Rinaldi, Gaetano Lambiase

备注：
20 pages, 6 figures, 1 table; With corrected proofs and bibliography, to be published in ApJ
发表信息：
ApJ, 912, 150 (2021)
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摘要：

Ia型超新星（SNe Ia）和普朗克测量值之间的哈勃常数（$H_0$）张力范围从4到6 $H_0$。为了研究这种紧张关系，我们通过将超新星Ia最大的汇编Pantheon样本分为3、4、20和40个箱来估计$Λ$ CDM和$w_{0}w_{a}$ CDM模型中的$H_{0}$。我们拟合提取的$H_{0}$值与一个函数模仿红移的演变：$g(z)={H_0}(z)=\tilde{H}_0/(1+z)^α$，其中$α$表示一个演变参数和$\tilde{H}_0=H_0$在$z=0$。我们设定Ia超新星的绝对星等，使$H_0=73.5\,\, \textrm{km s}^{-1}\,\textrm{Mpc}^{-1}$，并固定$Ω_{0m}^{ΛCDM}=0.298$和$Ω_{0m}^{w_{0}w_{a}CDM}=0.308$的基准值。我们发现$H_0$随红移的变化呈现出缓慢减小的趋势，只有在1.2 ~ 2.0PDMATHABMM范围内$α$系数与零一致。虽然$α$系数与0 in 3 $σ$相容，但这可能会影响宇宙学结果。我们在3个和4个箱中局部测量$H_0(z=0)-H_0(z=1)=0.4\, \textrm{km s}^{-1}\,\textrm{Mpc}^{-1}$的变化。外推${H_0}(z)$到$z=1100$，最后一个散射表面的红移，我们得到的值$H_0$兼容1 $σ$与普朗克测量独立的宇宙学模型和我们调查的箱数。因此，我们已经分别针对$Λ$ CDM和$w_{0}w_{a}$ CDM模型将$H_0$张力从$54\%$降低到$72\%$。如果$H_0(z)$的下降趋势是真实的，那么这可能是由于天体物理选择效应或修正的重力。

英文摘要：

The Hubble constant ($H_0$) tension between Type Ia Supernovae (SNe Ia) and Planck measurements ranges from 4 to 6 $σ$. To investigate this tension, we estimate $H_{0}$ in the $Λ$CDM and $w_{0}w_{a}$CDM models by dividing the Pantheon sample, the largest compilation of SNe Ia, into 3, 4, 20 and 40 bins. We fit the extracted $H_{0}$ values with a function mimicking the redshift evolution: $g(z)={H_0}(z)=\tilde{H}_0/(1+z)^α$, where $α$ indicates an evolutionary parameter and $\tilde{H}_0=H_0$ at $z=0$. We set the absolute magnitude of SNe Ia so that $H_0=73.5\,\, \textrm{km s}^{-1}\,\textrm{Mpc}^{-1}$, and we fix fiducial values for $Ω_{0m}^{ΛCDM}=0.298$ and $Ω_{0m}^{w_{0}w_{a}CDM}=0.308$. We find that $H_0$ evolves with redshift, showing a slowly decreasing trend, with $α$ coefficients consistent with zero only from 1.2 to 2.0 $σ$. Although the $α$ coefficients are compatible with 0 in 3 $σ$, this however may affect cosmological results. We measure locally a variation of $H_0(z=0)-H_0(z=1)=0.4\, \textrm{km s}^{-1}\,\textrm{Mpc}^{-1}$ in 3 and 4 bins. Extrapolating ${H_0}(z)$ to $z=1100$, the redshift of the last scattering surface, we obtain values of $H_0$ compatible in 1 $σ$ with Planck measurements independently of cosmological models and number of bins we investigated. Thus, we have reduced the $H_0$ tension from $54\%$ to $72\%$ for the $Λ$CDM and $w_{0}w_{a}$CDM models, respectively. If the decreasing trend of $H_0(z)$ is real, it could be due to astrophysical selection effects or to modified gravity.

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