从背景和增长率数据的组合重新考虑减速参数的非参数重建
Revisiting a non-parametric reconstruction of the deceleration parameter from combined background and the growth rate data
摘要：
宇宙减速参数$q$已重建的非参数的方式使用各种组合的最近的观测数据集。在这项工作中考虑了超新星（SN）距离模量数据的Pantheon汇编，宇宙计时器（CC）测量的哈勃参数，包括完整的系统学和重子声振荡（BAO）数据。从重建的$q$估计红移$z_t$，其中从过去的减速到后期的加速演化阶段发生的过渡。检查了普朗克2020估计的非零空间曲率的可能影响。包括不同的$H_0$测量结果，从最近的普朗克2020年和里斯2021年的探测器具有最大的差异，在$4.2σ$水平，进行了研究。结果表明，从过去的减速相到后期的加速相的转变发生在红移范围内$0.5<z<1$。对于$z>1$，在组合CC和SN数据的情况下，观察到重建的$q$具有非单调演化。在引入BAO数据时，重建的$q$显示出$z\gtrsim1$的振荡行为。为了研究物质扰动的影响，利用红移空间畸变（RSD）的生长率数据重建了$q$。使用$\mathcal{O}m(z)$诊断，我们得出推论的有效性$Λ$ CDM作为一致性检查。$Λ$ CDM模型具有良好的一致性，并在所有重建域中包含2 $σ$水平。
英文摘要：
The cosmic deceleration parameter $q$ has been reconstructed in a non-parametric way using various combinations of recent observational datasets. The Pantheon compilation of the Supernova (SN) distance modulus data, the Cosmic Chronometer (CC) measurements of the Hubble parameter including the full systematics and the Baryon Acoustic Oscillation (BAO) data have been considered in this work. The redshift $z_t$, where the transition from a past decelerated to a late-time accelerated phase of evolution occurs, is estimated from the reconstructed $q$. The possible effect of a non-zero spatial curvature from the Planck 2020 estimate is checked. The outcome of including different $H_0$ measurements from recent Planck 2020 and Riess 2021 probes having a maximum discrepancy at the $4.2σ$ level, is investigated. Results indicate that the transition from a past decelerated phase to the late-time accelerated phase occurs within the redshift range $0.5<z<1$. For $z>1$, the reconstructed $q$ is observed to have a non-monotonic evolution in case of the combined CC and SN data. On introducing the BAO data, the reconstructed $q$ shows an oscillating behaviour for $z\gtrsim1$. To investigate the effect of matter perturbations, the growth rate data from the Redshift-Space Distortions (RSD) are utilized in reconstructing $q$. Using the $\mathcal{O}m(z)$ diagnostic, we draw inferences on the validity of $Λ$CDM as a consistency check. The $Λ$CDM model is well consistent and included at the 2$σ$ level in the domain of all the reconstructions.
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。
