标题： 动态暗能量有必要吗？ DESI BAO 和修改的复合 显示英文标题

标题： Is Dynamical Dark Energy Necessary? DESI BAO and Modified Recombination

摘要： 最近由暗能量光谱仪器（DESI）对重子声学振荡（BAO）的测量，在平坦的$\Lambda$CDM 框架下解释时，与宇宙微波背景（CMB）和 Ia 型超新星（SN）观测表现出轻微到中等程度的矛盾。 这种差异已被引用作为动态暗能量（DDE）的证据。 鉴于 DDE 对基础物理的深远影响，我们探讨了是否可以通过修改再结合的物理过程来解决这一矛盾。 我们发现，一种现象学的再结合修改模型可以有效地调和 BAO 和 CMB 数据集，并且与 DDE 不同，它还预测了一个更高的哈勃常数$H_0$，从而部分缓解了哈勃矛盾。 对 BAO、CMB 和校准后的 SN 数据的全局拟合更倾向于再结合的修改而非 DDE。 显示英文摘要

摘要： Recent measurements of baryon acoustic oscillations (BAO) by the Dark Energy Spectroscopic Instrument (DESI) exhibit a mild-to-moderate tension with cosmic microwave background (CMB) and Type Ia supernova (SN) observations when interpreted within a flat $\Lambda$CDM framework. This discrepancy has been cited as evidence for dynamical dark energy (DDE). Given the profound implications of DDE for fundamental physics, we explore whether the tension can instead be resolved by modifying the physics of recombination. We find that a phenomenological model of modified recombination can effectively reconcile the BAO and CMB datasets and, unlike DDE, also predicts a higher Hubble constant $H_0$, thereby partially alleviating the Hubble tension. A global fit to BAO, CMB, and calibrated SN data favors modified recombination over DDE.