标题： 通过全形状星系聚类分析测试幻影交叉的特征 显示英文标题

标题： Testing Signatures of Phantom Crossing through Full-Shape Galaxy Clustering Analysis

摘要： 最近对重子声学振荡（BAO）的观测来自暗能量光谱巡天仪器（DESI）调查，当与宇宙微波背景（CMB）和I型超新星（SNIa）测量结果结合时，提供了晚期时间出现幻影穿越的有力证据，同时显示出与标准$\Lambda$CDM 模型的统计显著偏差。 在本工作中，我们通过使用来自重子振荡光谱巡天（BOSS）数据发布12（DR12）样本的预重建全形状（FS）星系功率谱，研究了红移空间星系聚集数据的作用。 该数据集与DESI数据发布2（DR2）的BAO测量以及各种SNIa样本一起进行分析。 我们的分析表明，这些数据集的联合组合可以在高达$\sim 5\sigma$的显著性水平上产生对$\Lambda$CDM 的偏差，表明暗能量状态方程参数$w(z)$可能在红移范围$z \sim 0.4$--$0.5$内穿越了幻影分界（$w = -1$）。 这种穿越的精确位置和强度取决于所采用的理论参数化方法。 重要的是，我们的结果表明，即使没有CMB数据，这一趋势仍然存在，强调了FS功率谱作为测试暗能量模型和区分竞争宇宙学情景的强大且独立探针的稳健性。 显示英文摘要

摘要： Recent observations of baryon acoustic oscillations (BAO) from the Dark Energy Spectroscopic Instrument (DESI) survey, when combined with measurements of the cosmic microwave background (CMB) and Type Ia supernovae (SNIa), provide compelling evidence for a phantom crossing at late times, along with statistically significant deviations from the standard $\Lambda$CDM model. In this work, we investigate the role of redshift-space galaxy clustering data by employing the pre-reconstruction full-shape (FS) galaxy power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) data release 12 (DR12) sample. This dataset is analyzed in combination with BAO measurements from DESI data release 2 (DR2) and various SNIa samples. Our analysis demonstrates that the joint combination of these datasets can yield deviations from $\Lambda$CDM at a significance level of up to $\sim 5\sigma$, suggesting strong indications that the dark energy equation of state parameter $w(z)$ may have crossed the phantom divide ($w = -1$) in the redshift range $z \sim 0.4$--$0.5$. The precise location and strength of this crossing depend on the adopted theoretical parameterizations. Importantly, our results reveal that this trend persists even in the absence of CMB data, underscoring the robustness of the FS power spectrum as a powerful and independent probe for testing dark energy models and for distinguishing between competing cosmological scenarios.