标题： 晚期宇宙膨胀中振荡的不可避免的表现 显示英文标题

标题： Inevitable manifestation of wiggles in the expansion of the late Universe

摘要： 利用宇宙微波背景辐射最后散射面的共动角直径距离几乎不受模型独立约束这一事实，我们证明了对于任何在背景动力学上与标准$\Lambda$冷暗物质模型在$z\sim0$处一致且最后散射时共动声horizon大小也一致的模型，哈勃半径相对于标准$\Lambda$冷暗物质模型的偏差必须属于一组可接受的小波集合。 由该框架刻画的模型族在定义宇宙运动学的各种函数中也表现出非平凡的振荡行为，即使这些小波本身非常简单。 我们还讨论了将这些运动学属性归因于暗能量以及引力耦合强度变化的后果。 利用一些最简单的小波，我们展示了该框架在描述重子声波振荡（BAO）数据方面的能力，无需对宇宙微波背景测量结果的一致性进行任何修改。 该框架还自然地解释了在非参数观测重建的哈勃参数和暗能量密度中发现的峰谷现象，认为这些峰谷现象是对某些BAO数据所暗示的谷峰的补偿，并质疑它们存在的物理真实性。 我们注意到，在基于与宇宙微波背景和局部$H_0$测量结果一致但受限于BAO数据的模型之上应用该框架，可以通过小波的波动性质来自然地容纳BAO数据，从而复活这些模型。 最后，我们还建议通过施加来自可行宇宙学模型或基本物理第一原理（如能量条件）的预期运动学特性，进一步缩小可接受小波的可能集合，以改进我们的框架。 显示英文摘要

摘要： Using the fact that the comoving angular diameter distance to the last scattering surface is strictly constrained almost model independently, we show that, for any model agreeing with the standard $\Lambda$CDM model on its background dynamics at $z\sim0$ and size of the comoving sound horizon at last scattering, the deviations of the Hubble radius from the one of the standard $\Lambda$CDM model must be a member of the set of admissible wavelets. The family of models characterized by this framework also offers nontrivial oscillatory behaviours in various functions that define the kinematics of the Universe, even when the wavelets themselves are very simple. We also discuss the consequences of attributing these kinematics to, first, dark energy, and second, varying gravitational coupling strength. Utilizing some simplest wavelets, we demonstrate the competence of this framework in describing the baryon acoustic oscillation (BAO) data without any modifications to the agreement with cosmic microwave background measurements. This framework also provides a natural explanation for the bumps found in nonparametric observational reconstructions of the Hubble parameter and dark energy density as compensations of the dips suggested by some BAO data, and questions the physical reality of their existence. We note that utilizing this framework on top of the models that agree with both the cosmic microwave background and local $H_0$ measurements but are held back by BAO data, one may resurrect these models through the wiggly nature of wavelets that can naturally accommodate the BAO data. Finally, we also suggest narrowing the plausible set of admissible wavelets to further improve our framework by imposing conditions from expected kinematics of a viable cosmological model or first principle fundamental physics such as energy conditions.