Title: Cosmology with a Non-minimally Coupled Dark Matter Fluid I. Background Evolution Show Chinese title

Title: 与非最小耦合暗物质流体的宇宙学 I. 背景演化

Abstract: We explore a cosmological model in which dark matter is non-minimally coupled to gravity at the fluid level. While typically subdominant compared to Standard Model forces, such couplings may dominate dark matter dynamics. We show that this interaction modifies the early-time Friedmann equations, driving a phase of accelerated expansion that can resolve the horizon and flatness problems without introducing additional fields. At even earlier times, the coupling to spatial curvature may give rise to a cosmological bounce, replacing the initial singularity of standard cosmology. These results suggest that non-minimally coupled dark matter could offer a unified framework for addressing both the singularity and fine-tuning problems. Show Chinese abstract

Abstract: 我们探索一种宇宙学模型，其中暗物质在流体层面上与引力非最小耦合。 尽管通常相比标准模型力是次主导的，这种耦合可能主导暗物质的动力学。 我们表明，这种相互作用修改了早时期弗里德曼方程，引发加速膨胀阶段，可以在不引入额外场的情况下解决视界和平坦性问题。 在更早的时间，对空间曲率的耦合可能导致宇宙反弹，取代标准宇宙学中的初始奇点。 这些结果表明，非最小耦合的暗物质可能为解决奇点和微调问题提供一个统一的框架。