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arXiv 2202.01202astro-ph.COgr-qchep-th
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后期扩展能解决$H_0$和$σ_8$之间的紧张关系吗?

Can late-time extensions solve the $H_0$ and $σ_8$ tensions?

Lavinia Heisenberg, Hector Villarrubia-Rojo, Jann Zosso

摘要:

我们分析的属性,任何后期修改的$Λ$ CDM扩展历史必须有,以始终解决这两个$H_0$和$σ_8$紧张局势。采用模型独立的方法,我们得到了一组必要条件,可以应用到通用的后期扩展。我们的结果是充分的分析,仅仅是基于假设,从$Λ$ CDM背景的偏差仍然很小。对于具有$w(z)$状态方程的暗能量流体的具体情况,我们推导出以下一般要求:(i)在某些$z$处求解$H_0$张力要求$w(z)<-1$(ii)求解$H_0$和$σ_8$张力要求$w(z)$穿过幻影鸿沟。最后,我们还允许有效引力常量有小的偏差。在这种情况下,我们的方法仍然能够约束这些偏差的函数形式。

英文摘要:

We analyze the properties that any late-time modification of the $Λ$CDM expansion history must have in order to consistently solve both the $H_0$ and the $σ_8$ tensions. Taking a model-independent approach, we obtain a set of necessary conditions that can be applied to generic late-time extensions. Our results are fully analytical and merely based on the assumptions that the deviations from the $Λ$CDM background remain small. For the concrete case of a dark energy fluid with equation of state $w(z)$, we derive the following general requirements: (i) Solving the $H_0$ tension demands $w(z)<-1$ at some $z$ (ii) Solving both the $H_0$ and $σ_8$ tensions requires $w(z)$ to cross the phantom divide. Finally, we also allow for small deviations on the effective gravitational constant. In this case, our method is still able to constrain the functional form of these deviations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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