宇宙学 tensions 的统一暗 sector 方法
Unified dark sector approaches to cosmological tensions
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中文总结 AI 辅助
该研究提出最小质量可变暗物质模型，利用单个标量场控制暗物质质量，可同时解决早期和晚期宇宙学 tensions，还能降低 $S_8$ 且无需额外微调，为相关研究提供了简单框架。
中文摘要 AI 辅助
我们对最小质量可变暗物质模型开展分析研究，其中单个标量场控制暗物质质量，重点关注其在同时解决多个宇宙学 tensions 方面的效用。我们表明，这类最小模型可自然地在宇宙历史的两个关键时期（物质-辐射相等时期和当前时期）发挥作用，产生类似早期暗能量的能量注入（受哈勃 tension 驱动），以及出现虚光子穿越（由 DESI 项目的重子声学振荡数据表明）。关键的是，这些效应的特征时间与宇宙学背景演化本身相关，而非特定能量尺度。此外，中间演化会降低成团物质密度，因此可降低 $S_8$（与数据偏好方向一致），同时避免新的长程相互作用。我们推导分析论据以理解同一模型中这些效应出现的条件，并评估其是否可在不引入额外微调的情况下发生。这为识别哪些势和与暗物质的耦合可同时影响早期和晚期宇宙学 tensions 提供了简单框架。
英文摘要
We present an analytical study of minimal mass-varying dark matter models, in which a single scalar field controls the dark matter mass, focusing on their utility in simultaneously addressing multiple cosmological tensions. We show that such minimal models can naturally become relevant at two critical epochs in the history of the Universe; matter-radiation equality and the present day, generating an early dark energy-like energy injection, as motivated by the Hubble tension, and an apparent phantom crossing, as suggested by baryon acoustic oscillation data from the DESI project. Crucially, the characteristic timing of these effects is tied to the cosmological background evolution itself, rather than specific energy scales. In addition, the intermediate evolution reduces the clustering matter density and can therefore lower $S_8$, in the direction preferred by data, while avoiding new long-range interactions. We derive analytic arguments to understand the conditions for these effects to arise in the same model and assess whether they can occur without introducing additional fine-tuning. This provides a simple framework for identifying which potentials and couplings to dark matter can simultaneously affect early- and late-time cosmological tensions.
