AI 中文总结
研究暗物质与重子通过纯动量转移相互作用的宇宙学模型，推导方程并在多种玻尔兹曼求解器中实现，证明代码一致性，还展示其对解决$\sigma_8$张力有用，加入低红移数据集后相互作用情形更受青睐。
AI 中文摘要
我们考虑一个暗物质和重子通过纯动量转移相互作用的宇宙学模型。我们阐述了这种相互作用的基础并推导其主要方程。在此框架下，只有两个相互作用组分的欧拉方程与标准情形不同。我们还解释了这种相互作用与许多玻尔兹曼求解器中常用的紧密耦合近似方案的关系。之后，我们在依赖紧密耦合近似方案的CLASS和CAMB玻尔兹曼求解器以及无近似方案的SymBoltz中实现该模型。我们证明了不同代码实现间的完全一致性。通过在较小尺度上产生减少的聚类，我们展示了这种相互作用对解决$\sigma_8$张力是有用的。利用宇宙微波背景、重子声学振荡、Ia型超新星数据以及来自苏尼亚耶夫-泽尔多维奇团簇计数和DES第6年结果的低红移约束，我们表明当包含那些低红移数据集时，相互作用情形更受青睐。
英文摘要
We consider a cosmological model where dark matter and baryons interact via a pure momentum transfer. We present the foundations of the interaction and derive its main equations. In this framework, only the Euler equations for the two interacting components differ from those in the standard scenario. We also explain how this interaction relates with the common Tight-Coupling Approximation schemes typically used in many Boltzmann solver. After that, we implement the model in CLASS and CAMB Boltzmann solvers, which relay on those Tight-Coupling Approximation schemes and in SymBoltz, which is free from any approximation scheme. We demonstrate full consistency among all the implementations in the difference codes. We demonstrate how this type of interactions are useful regarding the $σ_8$ tension by producing a reduced clustering on smaller scales. Using cosmic microwave background, baryon acoustic oscillations, supernovae type Ia data and low-redshift constraints from Sunyaev-Zeldovich cluster counts and from DES year 6 results, we show the interacting scenario is mildly preferred when those low-redshift datasets are included.
Comments16 pages, 7 figures
