Poulin Vivian, Smith Tristan L, Karwal Tanvi, Kamionkowski Marc
Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA.
Department of Physics and Astronomy, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, USA.
Phys Rev Lett. 2019 Jun 7;122(22):221301. doi: 10.1103/PhysRevLett.122.221301.
Early dark energy (EDE) that behaves like a cosmological constant at early times (redshifts z≳3000) and then dilutes away like radiation or faster at later times can solve the Hubble tension. In these models, the sound horizon at decoupling is reduced resulting in a larger value of the Hubble parameter H_{0} inferred from the cosmic microwave background (CMB). We consider two physical models for this EDE, one involving an oscillating scalar field and another a slowly rolling field. We perform a detailed calculation of the evolution of perturbations in these models. A Markov Chain Monte Carlo search of the parameter space for the EDE parameters, in conjunction with the standard cosmological parameters, identifies regions in which H_{0} inferred from Planck CMB data agrees with the SH0ES local measurement. In these cosmologies, current baryon acoustic oscillation and supernova data are described as successfully as in the cold dark matter model with a cosmological constant, while the fit to Planck data is slightly improved. Future CMB and large-scale-structure surveys will further probe this scenario.
早期暗能量（EDE）在早期（红移z≳3000）表现得像一个宇宙学常数，然后在后期像辐射一样稀释或更快地稀释，这样可以解决哈勃张力问题。在这些模型中，解耦时的声视界减小，导致从宇宙微波背景（CMB）推断出的哈勃参数H₀值更大。我们考虑了这种EDE的两种物理模型，一种涉及振荡标量场，另一种涉及缓慢滚动场。我们对这些模型中微扰的演化进行了详细计算。对EDE参数的参数空间进行马尔可夫链蒙特卡罗搜索，并结合标准宇宙学参数，确定了从普朗克CMB数据推断出的H₀与SH0ES本地测量值一致的区域。在这些宇宙学模型中，当前的重子声学振荡和超新星数据与具有宇宙学常数的冷暗物质模型一样得到了成功描述，同时对普朗克数据的拟合略有改善。未来的CMB和大规模结构调查将进一步探索这种情况。
