Dark energy is believed to be responsible for the acceleration of the universe. In this paper, we reconstruct the dark energy scalar field potential $V(ϕ)$ using the Hubble parameter $H(z)$ through Gaussian Process analysis. Our goal is to investigate dark energy using various $H(z)$ datasets and priors. We find that the selection of prior and the $H(z)$ dataset significantly affects the reconstructed $V(ϕ)$. And we compare two models, Power Law and Free Field, to the reconstructed $V(ϕ)$ by computing the reduced chi-square. The results suggest that the models are generally in agreement with the reconstructed potential within a $3σ$ confidence interval, except in the case of Observational $H(z)$ data (OHD) with the Planck 18 (P18) prior. Additionally, we simulate $H(z)$ data to measure the effect of increasing the number of data points on the accuracy of reconstructed $V(ϕ)$. We find that doubling the number of $H(z)$ data points can improve the accuracy rate of reconstructed $V(ϕ)$ by 5$\%$ to 30$\%$.
Gaussian Processes Reconstruction of the Dark Energy Potential
标量场（SF）已经成为暗能量的自然候选者，因为它们是暴胀理论的主要成分。然而，这项工作不是假设标量场势的某种形式，而是直接从观测数据，即\textbf{Hubble and SNe Ia data}，重建SF势。我们表明，SF势的两种流行形式，即幂律和二次自由场，与由此获得的重建兼容，至少对于物质密度和曲率参数的先验的某些选择以及对于某些红移间隔。
Impact of a negative cosmological constant on the reconstruction of dark energy in light of DESI BAO data
School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, UCAS（杭州高等研究院基础物理与数学学院，UCAS）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；International Center for Theoretical Physics Asia-Pacific（亚太理论物理中心）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）
On the Stability of Dark Energy Scalar Field Reconstruction from SNe Ia Data
A. I. Alikhanian National Science Laboratory (Yerevan Physics Institute)（阿·伊·阿里哈尼扬国家科学实验室（埃里温物理研究所））；University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）
Probabilistic reconstruction of Dark Matter fields from biased tracers using diffusion models
Harvard University（哈佛大学）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森天体物理中心）；The NSF AI Institute for Artificial Intelligence and Fundamental Interactions（NSF人工智能与基础相互作用研究所）；Massachusetts Institute of Technology（麻省理工学院）
Holographic Ricci dark energy: Current observational constraints, quintom feature, and the reconstruction of scalar-field dark energy
在这项工作中，我们考虑的宇宙学约束的全息里奇暗能量提出的高等。[Phys. Rev. D 79，043511（2009）]，利用现有的观测数据。全息Ricci暗能量的主要特征由模型中的正数值参数$α$决定。当$α<1/2$时，全息里奇暗能量将表现出类似五等分的行为;即，它的状态方程将跨越宇宙常数边界$w=-1$。参数$α$只能通过观察确定。因此，利用观测数据约束参数$α$，对于刻画暗能量的演化特征和预测宇宙的命运具有非常重要的意义。本文利用307颗Ia型超新星的Union样本、Wilkinson微波各向异性探测器5年观测给出的宇宙微波背景位移参数和Sloan数字巡天的重子声学振荡测量结果，导出了全息Ricci暗能量模型的约束条件。联合分析给出了最佳拟合结果（$σ$不确定度为1）：$α=0.359^{+0.024}_{-0.025}$和$Ω_{\rm m0}=0.318^{+0.026}_{-0.024}$。也就是说，根据观测，全息利玛窦暗能量呈现出五分之一的特征。最后，根据宇宙学约束的结果，我们讨论了基于全息Ricci真空能量的标量场暗能量重构问题。
