发表机构
Institute of Theoretical Astrophysics, Universitetet i Oslo; Max Planck Computing and Data Facility; Alma Mater Studiorium - Università di Bologna; Center for Astrophysics and Cosmology, University of Nova Gorica; IFPU, Institute for Fundamental Physics of the Universe（奥斯陆大学理论天体物理研究所; 马克斯·普朗克计算与数据中心; 博洛尼亚大学; 新戈里察大学天体物理学与宇宙学中心; 基础宇宙物理学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出一种曲率耦合暗能量模型，可同时影响重组前和晚期宇宙演化，缓解H0张力，并在弱透镜和ISW信号中留下可观测特征。
AI 中文摘要
我们研究了一种曲率耦合暗能量模型，该模型可以在重组之前和晚期加速时期修改宇宙学演化。该模型属于标量-张量理论类别，其中精质场与里奇标量非最小耦合。我们通过一个平移的四次耦合 $f(\varphi)=\alpha(\varphi^2-\varphi_{\rm today}^2)^2$ 和一个逆幂律势 $V(\varphi)=\Lambda\varphi^{-\sigma}$ 来指定该模型，其中 $\varphi_{\rm today}$ 是一个常数，通过要求有效普朗克质量恢复其当今归一化来确定。我们在 $\mathtt{hi\\_class}$ 的修改版本中实现了该模型，并计算了其背景和线性宇宙学预测。这种特定形式的非最小耦合允许在晚期有效穿越幻影分界线，同时自然抑制当今与标准引力的偏差并满足局部引力约束。同时，标量场可以修改重组前的膨胀历史，将声学尺度向缓解 $H_0$ 张力所需的方向移动，同时在低红移时作为暗能量保持动力学相关性。对于此处研究的参数选择，我们发现与 $\Lambda$CDM 相比，膨胀历史、物质聚集和度规势谱存在百分之几十的偏差。引力势的修改演化在相对论性可观测量中留下了特征性印记，弱透镜功率在低多极处被抑制 $\mathcal{O}(20$-$40\\%)$，晚期 Integrated Sachs-Wolfe 信号发生量级为1的变化。总之，这些结果揭示了一个广泛的、尺度相关的现象学，这促使进行完整的参数空间分析和将当前的线性处理扩展到专门的非线性 $N$-体实现。
英文摘要
We study a curvature-coupled dark energy model that can modify cosmological evolution both before recombination and during the late-time accelerated era. The model belongs to the class of scalar-tensor theories, in which a quintessence field is non-minimally coupled to the Ricci scalar. We specify the model through a shifted quartic coupling, $f(φ)=α(φ^2-φ_{\rm today}^2)^2$, and an inverse power-law potential, $V(φ)=Λφ^{-σ}$, where $φ_{\rm today}$ is a constant fixed by requiring the effective Planck mass to recover its present-day normalization. We implement the model in a modified version of $\mathtt{hi\_class}$ and compute its background and linear cosmological predictions. This specific form of non-minimal coupling allows an effective crossing of the phantom divide at late times while naturally suppressing deviations from standard gravity today and satisfying local gravity constraints. At the same time, the scalar field can modify the expansion history before recombination, shifting the acoustic scale in the direction required to alleviate the $H_0$ tension, while remaining dynamically relevant as dark energy at low redshift. For the parameter choices studied here, we find tens-of-percent deviations from $Λ$CDM in the expansion history, matter clustering, and metric-potential spectra. The modified evolution of the gravitational potentials leaves characteristic signatures in relativistic observables, with weak-lensing power suppressed by $\mathcal{O}(20$-$40\%)$ at low multipoles and order-unity changes in the late Integrated Sachs-Wolfe signal. Together, these results reveal a broad, scale-dependent phenomenology that motivates both a full parameter-space analysis and an extension of the present linear treatment to a dedicated non-linear $N$-body implementation.
Comments50 pages, 13 figures. The code is available at https://github.com/abdolalibanihashemi/hi_class_CCDE
