基于星系尺度强透镜、Ia型超新星、重子声学振荡和宇宙计时器的后牛顿参数与宇宙曲率的联合模型无关约束
Joint Model-independent Constraints on the Post-Newtonian Parameter and Cosmic Curvature from Galaxy-scale Strong Lensing, SNe Ia, BAO, and Cosmic Chronometers
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中文总结 AI 辅助
本研究联合强透镜、Ia型超新星、重子声学振荡和宇宙计时器，模型无关地约束后牛顿参数γ_PPN和曲率Ω_k，结果与广义相对论一致，且暗能量模型选择不引入显著系统偏差。
中文摘要 AI 辅助
本研究旨在通过星系尺度强引力透镜（SGL）结合多种宇宙学探针，在千秒差距尺度上检验广义相对论（GR）的有效性。为避免基于GR的宇宙学模型假设所引发的循环性问题，我们在Friedmann-Lemaitre-Robertson-Walker（FLRW）度规中应用距离和规则，独立于任何宇宙学模型来约束后牛顿参数γ_PPN和空间曲率Ω_k。本研究引入了两项方法论改进：（i）用二阶切比雪夫正交多项式参数化暗能量演化因子，确保在整个红移范围内具有均匀的高收敛性，同时将Ω_k保留为显式自由参数；（ii）将原始的双探针配置（SGL + Ia型超新星）扩展为四探针联合分析，纳入重子声学振荡和宇宙计时器。我们的结果显示，在68%置信水平下，γ_PPN = 1.119（+0.072/-0.072），Ω_k = 0.101（+0.077/-0.076）。γ_PPN的值与GR预测的1在1.7σ内一致，而Ω_k则倾向于一个轻微开放的宇宙，平坦性在2σ内一致。以模型无关约束为基准，我们量化了八种代表性暗能量模型引起的γ_PPN系统偏移，发现所有偏移均可忽略不计，远低于基准1σ不确定性，在当前精度下无显著偏差。这些结果证实常规强透镜引力测试不引入可测量的系统偏差，验证了我们的模型无关框架。
英文摘要
This investigation aims to test the validity of general relativity (GR) on kiloparsec scales via galaxy-scale strong gravitational lensing (SGL) combined with multiple cosmological probes. To circumvent the circularity problem induced by the presumption of a cosmological model based on GR, we apply the distance sum rule in the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric to constrain the post-Newtonian parameter gamma PPN and spatial curvature Omega k independently of any cosmological model. The study introduces two methodological improvements: (i) parameterizing the dark-energy evolution factor with second-order Chebyshev orthogonal polynomials, which ensures uniformly high convergence across the full redshift baseline while retaining Omega k as an explicit free parameter; (ii) extending the original two-probe configuration (SGL + Type Ia supernovae) to a four-probe joint analysis that includes baryon acoustic oscillations and cosmic chronometers. Our results show that gamma PPN = 1.119 (+0.072/-0.072) and Omega k = 0.101 (+0.077/-0.076) at 68% confidence. The gamma PPN value is consistent with the GR prediction of unity at 1.7 sigma, while Omega k favors a mildly open universe, with flatness consistent at 2 sigma. Taking model-independent constraints as a benchmark, we quantify the systematic shift in gamma PPN induced by eight representative dark energy models, and find that all offsets are negligible, well below the baseline 1 sigma uncertainty, with no significant bias at current precision. These results confirm that conventional strong-lensing gravity tests introduce no measurable systematic bias, validating our model-independent framework.
发表机构
- School of Microelectronics and Artificial Intelligence, Kaili University（凯里学院微电子与人工智能学院）
- School of Physics and Electronics Science, Guizhou Normal University（贵州师范大学物理与电子科学学院）
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