通过高斯过程对霍恩德斯基子类进行重构
Reconstructions of Horndeski Subclasses by Gaussian Processes
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中文总结 AI 辅助
该研究根据晚期宇宙学数据，利用高斯过程贝叶斯技术从霍恩德斯基类中重构两个子类理论，发现布兰斯 - 迪克子类在\(z\in(0.4,1.7)\)范围更受青睐，立方伽利略子类在全红移范围支持标量场与引力修正及暗能量密度随时间演化。
中文摘要 AI 辅助
在这项工作中，我们根据各种晚期宇宙学数据，从霍恩德斯基类（最一般的具有二阶方程的标量 - 张量引力理论）中重构了两个子类理论。这些数据包括宇宙计时器对哈勃率的模型无关测量，以及重子声学振荡的哈勃率和距离测量。在考虑的修正引力家族中，标量场与引力非最小耦合，导致宇宙学尺度上引力常数随时间变化。所考虑的理论也与引力波传播速度的限制一致。通过高斯过程贝叶斯技术对霍恩德斯基理论的布兰斯 - 迪克和立方伽利略子类进行重构。我们发现，对于数据，最可能的高斯过程重构在\(z\in(0.4,1.7)\)范围内支持布兰斯 - 迪克子类的宇宙学，而对于立方伽利略子类，在整个红移观测范围内，最可能的重构确实支持标量场与引力的修正，其中暗能量密度随时间演化。
英文摘要
In this work we reconstruct two subclasses of theories from the Horndeski class, the most general scalar-tensor theories of gravity with second-order equations, according to a variety of late-universe cosmological data: model independent measurements of Hubble rate from Cosmic Chronometers, as well as Hubble rate and distance measurements from Baryonic Acoustic Oscillations. In the modified gravity family considered, the scalar field is non-minimally coupled to gravity leading to time variations in the gravitational constant at cosmological scales. The theories considered are also consistent with constraints on the propagation speed of gravitational waves. The reconstruction is carried out by using the Gaussian Processes bayesian technique either for the Brans-Dicke and the Cubic Galileon subclasses of Horndeski theory. We find that the most likely Gaussian Process reconstruction for the data favors a cosmology from the Brans-Dicke subclass over $Λ$CDM in the range $z \in (0.4, 1.7)$, and for the Cubic Galileon subclass we find that the most likely reconstruction indeed favors modifications of the scalar field to gravity with evolving dark energy density in the whole range of redshift observations.
