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arXiv 2101.08641astro-ph.CO
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Ia型超新星绝对星等的局部先验在宇宙学推论中的应用

On the use of the local prior on the absolute magnitude of Type Ia supernovae in cosmological inference

David Camarena, Valerio Marra

备注：
9 pages, 6 figures, 3 tables. Title changed to better describe the scope, expanded analysis and discussion, v3 reflects version accepted for publication in MNRAS; code and up-to-date values of the prior on the absolute magnitude of Type Ia supernovae are available at https://github.com/valerio-marra/CalPriorSNIa
发表信息：
MNRAS 504 (4), 5164-5171 (2021)
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摘要：

在非常低的红移（$z<0.1$）处突然发生幻影跃迁之前，暗能量一直表现为宇宙学常数，这似乎解决了哈勃常数的局域和高红移测定之间的>4 $σ$不一致，同时保持了$Λ$ CDM模型相对于其他观测量的唯象成功。在这里，我们证明了这样一个小棍状的暗能量不能解决$H_0$危机。其基本原因是用于导出局域$H_0$约束的超新星绝对星等$M_B$与拟合超新星、BAO和CMB数据所必需的$M_B$不相容，并且这种不一致不能通过在极低红移处的突然幻影跃迁来解决。我们利用这个例子来说明为什么在统计分析中最好采用$M_B$上的先验作为$H_0$上的先验的替代。这三个原因是：i）避免对低红移超新星进行潜在的重复计数，ii）避免假设宇宙学的有效性，特别是将减速参数固定为标准模型值$q_0=-0.55$，iii）在分析中包括$M_B$受局部校准约束的事实，否则在分析中会忽略的信息，使模型选择和参数约束都有偏差。我们提供了$M_B$相对于最近的万神殿和DES-SN 3 YR超新星目录的先验。我们还提供了一个高斯联合先验的$H_0$和$q_0$推广的先验$H_0$由SH 0 ES。

英文摘要：

A dark-energy which behaves as the cosmological constant until a sudden phantom transition at very-low redshift ($z<0.1$) seems to solve the >4$σ$ disagreement between the local and high-redshift determinations of the Hubble constant, while maintaining the phenomenological success of the $Λ$CDM model with respect to the other observables. Here, we show that such a hockey-stick dark energy cannot solve the $H_0$ crisis. The basic reason is that the supernova absolute magnitude $M_B$ that is used to derive the local $H_0$ constraint is not compatible with the $M_B$ that is necessary to fit supernova, BAO and CMB data, and this disagreement is not solved by a sudden phantom transition at very-low redshift. We make use of this example to show why it is preferable to adopt in the statistical analyses the prior on $M_B$ as an alternative to the prior on $H_0$. The three reasons are: i) one avoids potential double counting of low-redshift supernovae, ii) one avoids assuming the validity of cosmography, in particular fixing the deceleration parameter to the standard model value $q_0=-0.55$, iii) one includes in the analysis the fact that $M_B$ is constrained by local calibration, an information which would otherwise be neglected in the analysis, biasing both model selection and parameter constraints. We provide the priors on $M_B$ relative to the recent Pantheon and DES-SN3YR supernova catalogs. We also provide a Gaussian joint prior on $H_0$ and $q_0$ that generalizes the prior on $H_0$ by SH0ES.

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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