发表机构
Anhui Normal University; Anhui Science and Technology University; Hunan Normal University（安徽师范大学; 安徽科技学院; 湖南师范大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文用三次和四次拉格朗日插值重建减速参数演化，基于DESI BAO、CMB和多种超新星数据，发现低红移偏离ΛCDM且加速减弱，但贝叶斯证据仍支持ΛCDM，频率论分析则偏好动态暗能量。
AI 中文摘要
本文基于最新的观测数据，利用三次和四次拉格朗日插值方法重建了减速参数的演化。这些数据包括来自DESI的重子声学振荡（BAO）测量、来自普朗克2018的宇宙微波背景（CMB）距离先验，以及三组Ia型超新星（SNe Ia）数据集：DES-Dovekie、Pantheon+和Union3。为了减轻数据在红移方向上非均匀分布的影响，我们不仅在标准红移$z$下进行重建，还在$y$-红移$y\equiv z/(1+z)$和对数红移$\zeta\equiv\ln(1+z)$下进行重建。来自DESI BAO+CMB+SNe Ia数据集的三次和四次$q(z)$重建表明，在低红移（$z<0.3$）处与$\Lambda$CDM模型存在明显偏差，支持当前宇宙加速比$\Lambda$CDM模型预测的更弱。重建的$q(z)$在整个演化过程中呈现出围绕$\Lambda$CDM模型的整体振荡模式。只有使用DESI BAO+CMB+Union3数据的三次-$y$和三次-$\zeta$重建提供了证据表明宇宙加速似乎已经达到最大值并开始减缓。然而，当纳入来自超新星和$H_0$状态方程（SH0ES）合作的哈勃常数$H_0$测量时，三次重建的$q(z)$演化向$\Lambda$CDM预测方向移动。无论是否存在$H_0$先验，所有重建都暗示减速-加速转变发生在$\Lambda$CDM模型预测的更早时刻。尽管如此，贝叶斯证据仍然支持$\Lambda$CDM，而频率论分析表明对拉格朗日插值重建有$>2\sigma$的偏好，暗示存在动态暗能量。
英文摘要
In this paper, we reconstruct the evolution of the deceleration parameter using cubic and quartic Lagrange interpolation methods, based on the latest observational data. This data includes baryon acoustic oscillation (BAO) measurements from DESI, cosmic microwave background (CMB) distance priors from Planck 2018, and three datasets of type Ia supernovae (SNe Ia): DES-Dovekie, Pantheon+, and Union3. To mitigate the impact of the nonuniform distribution of data in redshift, we carry out the reconstruction not only in the standard redshift $z$ but also in the $y$-redshift $y\equiv z/(1+z)$ and the log-redshift $ζ\equiv\ln(1+z)$. The cubic and quartic reconstructions of $q(z)$ from the DESI BAO+CMB+SNe Ia datasets indicate a clear deviation from the $Λ$CDM model at low redshift ($z<0.3$), supporting a weaker present-day cosmic acceleration than the predictions of the $Λ$CDM model. The reconstructed $q(z)$ exhibits an overall oscillatory pattern around the $Λ$CDM model throughout its evolution. Only the cubic-$y$ and cubic-$ζ$ reconstructions with the DESI BAO+CMB+Union3 data provide evidence that the cosmic acceleration appears to have already reached its maximum value and is beginning to slow down. However, when incorporating the measurement of the Hubble constant $H_0$ from the Supernovae and $H_0$ for the Equation of State (SH0ES) Collaboration, the evolution of $q(z)$ from cubic reconstructions shifts toward the $Λ$CDM prediction. Regardless of the presence or absence of the $H_0$ prior, all reconstructions imply that the deceleration-acceleration transition occurred earlier than predicted by the $Λ$CDM model. Nevertheless, the Bayesian evidence still favors $Λ$CDM, while the frequentist analysis indicates a $>2σ$ preference for the Lagrange-interpolation reconstructions, hinting at the existence of dynamical dark energy.
Comments14 pages, 5 figures; accepted for publication in Physical Review D
