发表机构
Manipur University（曼尼普尔大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过CC、DESI DR2 BAO及三种Ia型超新星汇编，对幂律f(Q)引力模型进行数据驱动检验，发现其能描述晚期宇宙加速，表现出类 quintessence 行为，与ΛCDM模型具有竞争力。
AI 中文摘要
晚期宇宙学观测的精度不断提升且具有互补性，为修正引力理论提供了新的机会，可通过观测到的宇宙膨胀历史对其进行检验。DESI DR2 BAO测量结果结合宇宙计时器（CC）与独立的Ia型超新星汇编，为宇宙加速提供了数据驱动的检验。受此进展的推动，我们采用幂律形式$f(Q)=\beta Q^{m+1}$，在对称平行f(Q)引力框架下研究晚期暗能量动力学，并通过有效状态方程（EoS）参数表征宇宙演化。该模型使用CC、DESI DR2 BAO以及三个独立的Ia型超新星汇编（即Pantheon+、DES-SN5YR和Union3）进行约束。推断得到的哈勃常数值相互一致，分别为$H_0=67.60^{+1.60}_{-1.66}$、$67.08^{+1.66}_{-1.61}$和$68.16^{+1.46}_{-1.43}\\,\mathrm{km\\,s^{-1}\\,Mpc^{-1}}$。统计上，所提出的f(Q)模型在所有数据集组合下均给出更低的$\chi^2_{\min}$值，且得到AIC的支持；而BIC在CC + DESI DR2 + Pantheon+和CC + DESI DR2 + DES-SN5YR组合下支持ΛCDM模型，对于CC + DESI DR2 + Union3组合则表明两种模型无显著偏好。重构的EoS显示出类 quintessence 行为，负的减速参数证实了当前的加速膨胀，减速到加速的转变发生在$0.680\leq z_t\leq0.745$范围内。高阶宇宙学参数以及Statefinder和$Om(z)$诊断均一致支持这种类 quintessence 行为，Statefinder轨迹在遥远未来趋近于ΛCDM不动点。总体而言，幂律f(Q)模型为晚期宇宙加速提供了可行且具有竞争力的描述。
英文摘要
The increasing precision and complementarity of late-time cosmological observations provide new opportunities to test modified gravity against the observed expansion history of the universe. The combination of DESI DR2 BAO measurements with cosmic chronometers (CC) and independent Type Ia supernova compilations provides a data-driven test of cosmic acceleration. Motivated by this progress, we investigate late-time dark energy dynamics in symmetric teleparallel $f(Q)$ gravity by adopting the power-law form $f(Q)=βQ^{m+1}$ and characterizing cosmic evolution through the effective equation of state (EoS) parameter. The model is constrained using CC, DESI DR2 BAO and three independent Type Ia supernova compilations, namely Pantheon+, DES-SN5YR and Union3. The inferred Hubble constant values are mutually consistent, yielding $H_0=67.60^{+1.60}_{-1.66}$, $67.08^{+1.66}_{-1.61}$ and $68.16^{+1.46}_{-1.43}\,\mathrm{km\,s^{-1}\,Mpc^{-1}}$, respectively. Statistically, the proposed $f(Q)$ model yields lower $χ^2_{\min}$ values and is favored by the AIC for all dataset combinations, whereas the BIC favors $Λ$CDM for the CC + DESI DR2 + Pantheon+ and CC + DESI DR2 + DES-SN5YR combinations and indicates no meaningful preference between the two models for the CC + DESI DR2 + Union3 dataset combinations. The reconstructed EoS indicates quintessence-like behavior, while the negative deceleration parameter confirms the current accelerated expansion. The transition from deceleration to acceleration occurs within $0.680\leq z_t\leq0.745$. Higher-order cosmographic parameters and the Statefinder and $Om(z)$ diagnostics consistently support this quintessence-like behavior, with the Statefinder trajectories approaching the $Λ$CDM fixed point in the far future. Overall, the power-law $f(Q)$ model provides a viable and competitive description of late-time cosmic acceleration.
