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Constraints on the spacetime dynamics of an early dark energy component
Journal of Cosmology and Astroparticle Physics ( IF 6.4 ) Pub Date : 2020-07-15 , DOI: 10.1088/1475-7516/2020/07/039
Hasti Khoraminezhad 1, 2, 3 , Matteo Viel 1, 2, 3, 4 , Carlo Baccigalupi 1, 2, 3 , Maria Archidiacono 5, 6
Affiliation  

We consider an Early Dark Energy (EDE) cosmological model, and perform an analysis which takes into account both background and perturbation effects via the parameters $c^{2}_{\rm eff}$ and $c^{2}_{\rm vis}$, representing effective sound speed and viscosity, respectively. By using the latest available data we derive constraints on the amount of dark energy at early times and the present value of the equation of state. Our focus is on the effect that early dark energy has on the Cosmic Microwave Background (CMB) data, including polarization and lensing, in a generalized parameter space including a varying total neutrino mass, and tensor to scalar ratio, besides the 6 standard parameters of the minimal cosmological model. We find that the inclusion of Baryonic Acoustic Oscillations (BAO) data and CMB lensing significantly improves the constraints on the EDE parameters, while other high redshift data like the Quasar Hubble diagram and the Lyman-$\alpha$ forest BAO have instead a negligible impact. We find $\Omega_{\rm eDE} < 0.00391 $ and $w_{0} < -0.9500 $ at the $95 \%$ C.L. for EDE accounting for its clustering through the inclusion of perturbation dynamics. This limit becomes weaker $\Omega_{\rm eDE} < 0.00337$ if perturbations are neglected. The constraints on the EDE parameters are remarkably stable even when $\Sigma m_{\nu}$, and $r$ parameters are varied, with weak degeneracies between $\Omega_{\rm eDE}$ and $r$ or $\Sigma m_{\nu}$. Perturbation parameters are not constrained with current data sets, and tensions between the CMB derived $H_0$ and $\sigma_8$ values and those measured with local probes are not eased. This work demonstrates the capability of CMB probes to constrain the total amount of EDE well below the percent level.

中文翻译:

对早期暗能量成分时空动力学的约束

我们考虑早期暗能量 (EDE) 宇宙学模型,并通过参数 $c^{2}_{\rm eff}$ 和 $c^{2}_{ 进行考虑背景和扰动效应的分析\rm vis}$,分别代表有效声速和粘度。通过使用最新的可用数据,我们推导出对早期暗能量数量和状态方程现值的约束。我们的重点是早期暗能量对宇宙微波背景 (CMB) 数据的影响,包括偏振和透镜,在广义参数空间中,包括变化的总中微子质量和张量与标量之比,以及 6 个标准参数最小宇宙学模型。我们发现包含重子声学振荡 (BAO) 数据和 CMB 透镜显着改善了对 EDE 参数的约束,而其他高红移数据,如类星体哈勃图和 Lyman-$\alpha$ 森林 BAO 的影响可以忽略不计. 我们发现 $\Omega_{\rm eDE} < 0.00391 $ 和 $w_{0} < -0.9500 $ 在 $95 \%$ CL 处 EDE 通过包含扰动动力学来解释其聚类。如果忽略扰动,这个限制会变得更弱 $\Omega_{\rm eDE} < 0.00337$。即使 $\Sigma m_{\nu}$ 和 $r$ 参数变化,对 EDE 参数的约束也非常稳定,$\Omega_{\rm eDE}$ 和 $r$ 或 $\Sigma 之间存在弱退化m_{\nu}$。扰动参数不受当前数据集的约束,并且 CMB 导出的 $H_0$ 和 $\sigma_8$ 值与使用本地探针测量的值之间的张力没有缓解。这项工作证明了 CMB 探针将 EDE 总量限制在远低于百分比水平的能力。
更新日期:2020-07-15
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