论文标题
宇宙学参数中的全息能密度，深色能量速度和紧张局势：$ H_0 $和$ S_8 $
Holographic energy density, dark energy sound speed, and tensions in cosmological parameters: $H_0$ and $S_8$
论文作者
论文摘要
宇宙学参数中有趣的差异正在挑战$λ$ CDM模型的成功。使用CepheID变量和超新星的直接测量hubble常数$ H_0 $结果比宇宙微波背景（CMB）推断出的要高。弱星系镜头调查一致地报告物质强度的值$σ_8$比$λ$ cdm的上下文中从CMB得出的值低。在本文中，我们通过将暗能量（de）视为具有进化状态$ w _ {\ mathrm {de}}（z）$的液体来解决这些差异，恒定声速平方$ \ hat $ \ hat {c} _ {我们的$ w _ {\ mathrm {de}}（z）$源自全息原理，可以连续表现出类似辐射的，类似物质的和类似的行为，从而影响了声音范围，从而影响了声音范围，因此com comoving angulting angular diamemeter距离，因此，$ h_0 $ $ h_0 $。在这里，我们通过对重力势的演变的影响来表明，声速在物质聚类行为中起着作用。我们使用多种数据集组合来计算宇宙学的约束，包括主要CMB，CMB镜头，红移空间降低，局部距离驱动器，超新星和Baryon声学振荡。在我们的分析中，我们在$ \ hat {c} _ {\ mathrm {s}}^{2} $上边缘化，找到$ \ gtrsim3σ$，找到$ \ hat {c} _ {c} _ {c} _ {\ hatrm {\ mathrm {s}}}^{2} = 1 $。对于我们的基线结果，包括整个数据集，我们发现$ H_0 $和$σ_8$在良好的协议中（$ \ \ \ \2σ$之内），以及低红移探针。然而，我们对Baryon Energy密度$ω_{\ rm {B}} $的约束是在$ \3σ$张力中具有BBN约束。我们得出的结论还具有非标准聚类属性[例如，$ \ hat {c} _ {\ mathrm {s}}}^{2}^{2}（z，k）$]可能与解决宇宙学参数中当前差异的解决方案有关。
Interesting discrepancies in cosmological parameters are challenging the success of the $Λ$CDM model. Direct measurements of the Hubble constant $H_0$ using Cepheid variables and supernovae turn out to be higher than inferred from the Cosmic Microwave Background (CMB). Weak galaxy lensing surveys consistently report values of the strength of matter clustering $σ_8$ lower than values derived from the CMB in the context of $Λ$CDM. In this paper we address these discrepancies in cosmological parameters by considering Dark Energy (DE) as a fluid with evolving equation of state $w_{\mathrm{de}}(z)$, constant sound speed squared $\hat{c}_{\mathrm{s}}^{2}$, and vanishing anisotropic stress $σ$. Our $w_{\mathrm{de}}(z)$ is derived from the Holographic Principle and can consecutively exhibit radiation-like, matter-like, and DE-like behaviour, thus affecting the sound horizon and the comoving angular diameter distance, hence $H_0$. Here we show DE sound speed plays a part in the matter clustering behaviour through its effect on the evolution of the gravitational potential. We compute cosmological constraints using several data set combinations including primary CMB, CMB lensing, redshift-space-distortions, local distance-ladder, supernovae, and baryon acoustic oscillations. In our analysis we marginalise over $\hat{c}_{\mathrm{s}}^{2}$ and find $\hat{c}_{\mathrm{s}}^{2}=1$ is excluded at $\gtrsim 3σ$. For our baseline result including the whole data set we found $H_0$ and $σ_8$ in good agreement (within $\approx 2σ$) with low redshift probes. Our constraint for the baryon energy density $ω_{\rm{b}}$ is however in $\approx 3σ$ tension with BBN constraints. We conclude evolving DE also having non-standard clustering properties [e.g., $\hat{c}_{\mathrm{s}}^{2}(z,k)$] might be relevant for the solution of current discrepancies in cosmological parameters.
