论文标题
通用修改重力调查的后期和大爆炸核合成约束
Late-time and Big Bang nucleosynthesis constraints for generic modify gravity surveys
论文作者
论文摘要
在这项工作中，提出了$ f（r）$理论的新通用参数化。我们对新的状态方程式的提议可以重现$ f（r）$ - 就像进化一样，当我们使用基于宇宙天元素的距离梯子测量的组合时，描述了1- $σ$ c.l的晚期和早期宇宙。实际上，根据延迟测量，对$ f（r）$ f（r）$ cosmological可行的场景进行了广泛的分析，而与该理论的字段方程相比，EOS的精度优于$ 99.2 \％$。此外，在此提案中，我们扩展了研究，以在很早的时间内找到约束，以满足氦气部分的大爆炸核合成数据，$ y_ {p} $。进行此分析，并使用我们的通用$ W_ {f（r）} $ - 似乎可以在管道中与其他参数相同的水平和观察性调查的分析 - 我们考虑了背景和线性扰动进化和限制，超出了标准$ CDM六宇宙学参数。 While there are strong constraints at background on the free parameters of our $w_{f(R)}$, we found that $f(R)$ background viable models can set early constraints to the current Hubble constant $H_0$, which is in agreement with CMB data, but when late-time model-independent measurements are considered, $H_0$ is fully compatible with the $R^{H18}$ value.最后，作为这些结果的扩展，我们的建议能够在距离梯子的两个路线上区分$ f（r）$方案，以显示在此级别上修改重力的良好方法。
In this work, a new generic parameterisation for $f(R)$ theories is presented. Our proposal for a new equation of state can reproduce an $f(R)$-like evolution that describes late and early time universe within 1-$σ$ C.L when we use a combination of distance ladder measurements based on Cosmic Chronometers, Supernovae Ia, Baryon Acoustic Oscillation and finally, Cosmic Microwave Background and Lyman-$α$ forest. Indeed, a family of $f(R)$ cosmological viable scenarios were extensively analysed in the light of late-time measurements, were an Eos reaches a precision better than $99.2\%$ over the numerical solutions for the field equations of this theory. Moreover, in this proposal we extended the study to find constraints at the very early time that can satisfy the Big Bang Nucleosynthesis data on helium fraction, $Y_{p}$. To perform this analysis, and with our generic $w_{f(R)}$ --which can be seemed it at the same level as other parameterisations into the pipeline and analysis of observational surveys-- we consider both background and linear perturbations evolution and constrain beyond the standard $Λ$CDM six cosmological parameters. While there are strong constraints at background on the free parameters of our $w_{f(R)}$, we found that $f(R)$ background viable models can set early constraints to the current Hubble constant $H_0$, which is in agreement with CMB data, but when late-time model-independent measurements are considered, $H_0$ is fully compatible with the $R^{H18}$ value. Finally, as an extension of these results, our proposal is capable to distinguish between $f(R)$ scenarios at both routes of the distance ladder showing a good approach to modify gravity at this level.
