发表机构
University of Trento; Trento Institute for Fundamental Physics and Applications (TIFPA)-INFN; University of Sheffield（特伦托大学; 特伦托基础物理与应用研究所（TIFPA）-意大利国家核物理研究所; 谢菲尔德大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过三级受控比较策略，剖析相互作用暗能量模型相对ΛCDM的真实宇宙学特征，发现固定θ_s和z_eq后CMB谱几乎不可区分，而物质功率谱差异显著，强调精确测定Ω_m的重要性。
AI 中文摘要
相互作用暗能量（IDE）模型，以暗物质（DM）和暗能量（DE）之间的相互作用为特征，已受到显著的重新关注。然而，很少有研究致力于理解其真正的宇宙学特征，与ΛCDM的比较通常是在固定宇宙学参数下进行的。考虑到广泛研究的能量交换率与DE密度成正比的模型，我们进行了三级比较序列，从朴素的固定参数比较开始，然后补偿θ_s和z_eq的偏移，然后消除由于修改后的背景所产生的影响。我们表明，固定θ_s和z_eq会导致Weyl势、光子单极子和重子速度的再复合前演化与ΛCDM对应物几乎相同，因此宇宙微波背景（CMB）温度功率谱几乎无法区分。将IDE与具有相同背景的非相互作用wCDM模型进行比较，我们在CMB透镜中发现了小尺度依赖的特征。我们在物质功率谱中发现了更大的差异，反映了暗区划分为DM和DE的不同分割所导致的Ω_m的不同值，而一旦我们比较Ω_m^2P_m(k)，仅剩百分级别差异，这表明高精度确定Ω_m的重要性。我们受控的比较策略可以成为超越ΛCDM的广泛模型的有力工具。
英文摘要
Interacting dark energy (IDE) models, featuring interactions between dark matter (DM) and dark energy (DE), have received significant renewed interest. However, little attention has been devoted to understanding their genuine cosmological signatures, with comparisons against $Λ$CDM often carried out at fixed cosmological parameters. Considering the widely studied model with energy exchange rate proportional to the DE density, we carry out a three-level sequence of comparisons, starting from the naïve fixed-parameter comparison, then compensating for shifts in $θ_s$ and $z_{\text{eq}}$, and then removing effects due to the modified background. We show that fixing $θ_s$ and $z_{\text{eq}}$ leads to pre-recombination evolutions of the Weyl potential, photon monopole, and baryon velocity which are nearly identical to their $Λ$CDM counterparts, and hence virtually indistinguishable Cosmic Microwave Background (CMB) temperature power spectra. Comparing IDE to a non-interacting $w$CDM model with the same background, we find small scale-dependent signatures in CMB lensing. We find larger differences in the matter power spectrum, reflecting the different values of $Ω_m$ resulting from the different partition of the dark sector into DM and DE, with only percent-level differences remaining once we compare $Ω_m^2P_m(k)$, indicating the importance of high-fidelity determinations of $Ω_m$. Our controlled comparison strategy can be a powerful tool for a wide range of models beyond $Λ$CDM.
Comments32 pages, many sub-figures and sub-panels arranged in 11 figures, many references. CLASS_IDE publicly available at https://github.com/msabogal/CLASS_IDE
