AI 中文总结
利用模型无关样条重建宇宙晚期膨胀历史，结合最新测量与超新星汇编，与 ΛCDM 模型比较，在 0.3≤z≤0.6 识别局部偏差，最大显著性约 3.5σ，该特征稳定，或指向新晚期物理或揭示宇宙学探测器不一致。
AI 中文摘要
我们基于最新的 DESI DR2 重子声学振荡（BAO）测量和 DES 多夫基 Ia 型超新星汇编，使用宇宙学距离的模型无关样条重建来研究宇宙的晚期膨胀历史。将重建的膨胀历史与普朗克 2018 ΛCDM 模型的预测进行比较，我们在红移区间 0.3≤z≤0.6 内识别出一个局部偏差，在 z≈0.47 时达到约 3.5σ 的最大显著性。我们证明，在重建方法、数据集组成和声视界校准的大量变化下，这一特征仍然存在。模拟分析进一步表明，重建是无偏的，且观测到的异常不太可能源于重建偏差或校准错误的不确定性。如果被未来观测证实，这个局部特征可能指向以前未被认识的晚期物理，或揭示早期和晚期宇宙学探测器之间的细微不一致。
英文摘要
We investigate the late-time expansion history of the Universe using a model-independent spline reconstruction of cosmological distances based on the latest DESI DR2 baryon acoustic oscillation (BAO) measurements and the DES Dovekie Type Ia supernova compilation. Comparing the reconstructed expansion history with the prediction of the Planck 2018 $Λ$CDM model, we identify a localized deviation over the redshift interval $0.3\lesssim z\lesssim0.6$, reaching a maximum significance of approximately $3.5σ$ at $z\simeq0.47$. We demonstrate that this feature persists under substantial variations of the reconstruction methodology, dataset composition and sound-horizon calibration. Mock analyses further show that the reconstruction is unbiased and that the observed anomaly is unlikely to arise from reconstruction bias or miscalibrated uncertainties. If confirmed by future observations, this localized feature could point to previously unrecognized late-time physics or reveal subtle inconsistencies between early and late Universe cosmological probes.
Comments15 pages, 5 figures, comments are welcome
