RSD约束下使用Barboza-Alcaniz和Jassal-Bagla-Padmanabhan参数化的幂律$f(Q)$引力
RSD constraints on power-law $f(Q)$ gravity using Barboza-Alcaniz and Jassal-Bagla-Padmanabhan parametrizations
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- University Mohammed V in Rabat（拉巴特穆罕默德五世大学）
- University of Mohammed first（穆罕默德一世大学）
- Hassan II University of Casablanca（卡萨布兰卡哈桑二世大学）
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中文总结 AI 辅助
本文在幂律f(Q)引力中结合BA和JBP参数化，利用RSD等观测数据约束模型，发现其能解释晚期加速且有效引力常数小于牛顿常数，是ΛCDM的可行替代方案。
中文摘要 AI 辅助
我们研究了幂律$f(Q)$引力，$f(Q) = Q + 6\gamma H_0^2 \left(\frac{Q}{Q_0}\right)^n$，结合两种动态暗能量参数化，即Barboza-Alcaniz (BA)和Jassal-Bagla-Padmanabhan (JBP)，它们允许状态方程在标准常数$\omega$假设之外平滑演化，从而探讨宇宙晚期的加速膨胀。我们推导了哈勃参数和暗能量密度的解析表达式，并使用Pantheon$^+$ Ia型超新星、DESI DR2重子声学振荡和宇宙学计时器来约束模型。超越纯几何探针，我们纳入红移空间畸变（RSD）测量，以测试宇宙结构的增长，并通过有效牛顿常数区分修正引力与广义相对论。两种参数化都再现了观测到的晚期加速，并与增长数据保持一致，在低和中等红移下仅与$\Lambda$CDM存在轻微偏差。值得注意的是，两种配置都产生$G_{\rm eff} < G$，表明物质扰动增长受到抑制。这些结果确立了具有BA和JBP参数化的幂律$f(Q)$引力作为$\Lambda$CDM在背景和扰动领域均可行且多功能的替代方案。
英文摘要
We investigate the late-time accelerated expansion of the Universe in power-law $f(Q)$ gravity, $f(Q) = Q + 6γH_0^2 \left(\frac{Q}{Q_0}\right)^n$, combined with two dynamical dark energy parametrizations, Barboza-Alcaniz (BA) and Jassal-Bagla-Padmanabhan (JBP), which allow a smooth evolution of the equation of state beyond the standard constant $ω$ assumption. We derive analytical expressions for the Hubble parameter and the dark energy density, and constrain the model using Pantheon$^+$ Type Ia Supernovae, DESI DR2 Baryon Acoustic Oscillations, and Cosmic Chronometers. Going beyond purely geometrical probes, we incorporate Redshift Space Distortion (RSD) measurements to test the growth of cosmic structures and distinguish modified gravity from General Relativity through the effective Newton's constant. Both parametrizations reproduce the observed late-time acceleration and remain consistent with growth data, with only mild deviations from $Λ$CDM over low and intermediate redshifts. Notably, both configurations yield $G_{\rm eff} < G$, indicating suppressed growth of matter perturbations. These results establish power-law $f(Q)$ gravity with BA and JBP parametrizations as a viable and versatile alternative to $Λ$CDM across both background and perturbative regimes.
