论文标题
可以共耦合的改良重力能够解决哈勃张力吗？
Can Conformally Coupled Modified Gravity Solve The Hubble Tension?
论文作者
论文摘要
早期的推论与哈勃常数的直接测量之间的差异，被称为哈勃张力，最近成为高精度宇宙学的紧迫主题。结果，已经提出了各种各样的理论模型来缓解这种张力。在这项工作中，我们分析了由于标量场与RICCI标量偶联而导致的连形性重力（CCMG）模型，该模型是由于基于重新组合时增加声音水平的增加而在HUBBLE张力上偶性而活跃的RICCI标量。该模型在理论上是有利的，因为除了基线$λ$ CDM之外，它只有一个免费参数。受到所谓早期 - 能量模型的类似分析的启发，我们使用早期和晚期宇宙学数据集的组合来限制CCMG模型。 In addition to the Planck 2018 cosmic microwave background (CMB) anisotropies and weak lensing measurements, baryon acoustic oscillations and the Supernova H0 for the Equation of State datasets, we also use large-scale structure (LSS) datasets such as the Dark Energy Survey year 1 and the full-shape power spectrum likelihood from the Baryon Oscillation Spectroscopic Survey, including它使用有效的现场理论的最新分析，以检查CCMG模型对CMB和LSS之间（较轻）S8张力的影响。我们发现CCMG模型可以稍微放松哈勃张力，而$ H_0 = 69.6 \ pm 1.6 $ km/s/mpc的95％Cl，而几乎没有影响S8张力。但是，当前数据对CCMG的偏好与标准宇宙学模型相比表现出强烈的偏爱。最后，我们表明计划的CMB-S4实验将具有区分CCMG模型和涉及不断发展的重力常数的更通用模型所需的灵敏度。
The discrepancy between early-Universe inferences and direct measurements of the Hubble constant, known as the Hubble tension, recently became a pressing subject in high precision cosmology. As a result, a large variety of theoretical models have been proposed to relieve this tension. In this work we analyze a conformally-coupled modified gravity (CCMG) model of an evolving gravitational constant due to the coupling of a scalar field to the Ricci scalar, which becomes active around matter-radiation equality, as required for solutions to the Hubble tension based on increasing the sound horizon at recombination. The model is theoretically advantageous as it has only one free parameter in addition to the baseline $Λ$CDM ones. Inspired by similar recent analyses of so-called early-dark-energy models, we constrain the CCMG model using a combination of early and late-Universe cosmological datasets. In addition to the Planck 2018 cosmic microwave background (CMB) anisotropies and weak lensing measurements, baryon acoustic oscillations and the Supernova H0 for the Equation of State datasets, we also use large-scale structure (LSS) datasets such as the Dark Energy Survey year 1 and the full-shape power spectrum likelihood from the Baryon Oscillation Spectroscopic Survey, including its recent analysis using effective field theory, to check the effect of the CCMG model on the (milder) S8 tension between the CMB and LSS. We find that the CCMG model can slightly relax the Hubble tension, with $H_0 = 69.6 \pm 1.6$ km/s/Mpc at 95% CL, while barely affecting the S8 tension. However, current data does not exhibit strong preference for CCMG over the standard cosmological model. Lastly, we show that the planned CMB-S4 experiment will have the sensitivity required to distinguish between the CCMG model and the more general class of models involving an evolving gravitational constant.
