利用DESI DR2与强引力透镜时间延迟检验$f(Q)$引力
Testing $f(Q)$ Gravity with DESI DR2 and Strong-Lensing Time Delays
另 2 家 · 查看机构详情
- Henan Academy of Sciences（河南省科学院）
- GLA University（GLA大学）
- University of Delhi（德里大学）
- Symbiosis International (Deemed University)（西姆比奥西斯国际（认定）大学）
- Qingdao University of Science and Technology（青岛科技大学）
机构由 AI 辅助整理，请以论文原文为准。
浏览论文内容
中文总结 AI 辅助
本研究利用宇宙钟、DESI DR2、强引力透镜时间延迟及多组Ia型超新星数据，约束两种$f(Q)$引力模型的参数，发现其可作为无需宇宙学常数的$\u039b$CDM替代方案，解释宇宙晚期加速膨胀。
中文摘要 AI 辅助
对称远平行引力为引力提供了另一种描述框架，其中非度规性取代了曲率与挠率。通过$f(Q)$引力对其进行的拓展，为宇宙晚期膨胀及其加速阶段提供了不同的几何描述。在本研究中，我们探究了两种$f(Q)$模型——归一化幂律模型与平方根指数模型，并测试它们描述晚期膨胀历史的能力。我们利用宇宙钟测量、DESI DR2重子声学振荡、强引力透镜时间延迟观测，以及Pantheon$^+$、Union 3.0和DES Y5三个Ia型超新星数据集，通过马尔可夫链蒙特卡洛分析对模型参数进行约束。我们使用最小$\u03c7^2$、赤池信息准则和贝叶斯信息准则，将两种模型与平坦$\u039b$CDM模型进行对比。对于宇宙钟、DESI DR2、强引力透镜时间延迟数据分别与Pantheon$^+$、Union 3.0组合的数据集，平方根指数模型的统计拟合效果优于$\u039b$CDM，在拟合优度与信息准则上均有提升。对于包含超新星的组合数据集，归一化幂律模型在统计上仍与$\u039b$CDM具有竞争力，不过信息准则并不支持其额外参数的引入。我们还测定了两种模型下宇宙从减速膨胀到加速膨胀的转变红移，在不同数据集组合下得到的数值一致。这些转变红移与宇宙加速时期的观测估计值相符。总体而言，我们的结果支持$f(Q)$引力作为$\u039b$CDM的可行替代方案，无需宇宙学常数即可解释宇宙晚期的加速膨胀。
英文摘要
Symmetric teleparallel gravity provides an alternative description of gravitation in which non-metricity replaces curvature and torsion. Its extension through $f(Q)$ gravity offers a different geometric description of the late-time expansion of the Universe and its accelerated phase. In this work, we investigate two $f(Q)$ models, a normalized power-law model and a square-root exponential model, and test their ability to describe the late-time expansion history. We constrain the model parameters through Markov chain Monte Carlo analyses using Cosmic Chronometer measurements, DESI DR2 baryon acoustic oscillations, strong-lensing time-delay observations, and three Type Ia supernova compilations, Pantheon$^+$, Union 3.0, and DES Y5. We compare both models with the flat $Λ$CDM model using the minimum $χ^2$, Akaike information criterion, and Bayesian information criterion. The square-root exponential model provides a better statistical fit than $Λ$CDM for the combinations of Cosmic Chronometer, DESI DR2, and strong-lensing time-delay data with Pantheon$^+$ and Union 3.0, with improvements in both the goodness of fit and information criteria. The normalized power-law model remains statistically competitive with $Λ$CDM for the supernova-inclusive combinations, although the information criteria do not favor its additional parameter. We also determine the transition redshift from cosmic deceleration to acceleration for both models, obtaining consistent values across the different dataset combinations. The transition redshifts agree with observational estimates of the cosmic acceleration epoch. Overall, our results support $f(Q)$ gravity as a viable alternative to $Λ$CDM for explaining the late-time accelerated expansion of the Universe without requiring a cosmological constant.
