论文标题

一种新颖的早期黑暗能源模型

A novel early Dark Energy model

论文作者

García, Luz Ángela, Castañeda, Leonardo, Tejeiro, Juan Manuel

论文摘要

我们介绍了早期暗能量(EDE)模型的理论研究。在弗里德曼 - 莱米特雷 - 罗伯逊 - 漫游者宇宙的框架中,状态$ω(z)$的方程在热历史上演变,遵循有效的参数化,这是红移$ z $的函数。我们探索系统从辐射统治时代到后期的演变,使EDE模型在高红移时具有不可忽略的贡献(与仅在结构形成结构形成的作用时仅发挥作用的宇宙学常数相反),并且对大爆炸核合成的投入很少,并且在范围内的范围是散布的。在后期,暗能能模型的状态方程式渐近地倾向于De Sitter统治时期的基准价值,从而为近来的宇宙加速膨胀提供了解释,从而模仿了宇宙常数的效果。所提出的模型具有三个自由参数,我们使用SNIA光度距离以及CMB移位参数以及在暗能量时计算出的减速参数来限制。有了最适合我们模型的知识,我们计算出不同的可观察结果,并将这些预测与标准$λ$ CDM模型进行比较。除了具有宇宙常数的社区的一般同意外,没有基本理由选择特定候选人作为黑暗能量。在这里,我们为考虑一个更具动态模型的机会开放,这也解释了宇宙的晚期加速扩张。

We present a theoretical study of an early dark energy (EDE) model. The equation of state $ω(z)$ evolves during the thermal history in a framework of a Friedmann-Lemaitre-Robertson-Walker Universe, following an effective parametrization that is a function of redshift $z$. We explore the evolution of the system from the radiation domination era to the late times, allowing the EDE model to have a non-negligible contribution at high redshift (as opposed to the cosmological constant that only plays a role once the structure is formed) with a very little input to the Big Bang Nucleosynthesis, and to do so, the equation of state mimics the radiation behaviour, but being subdominant in terms of its energy density. At late times, the equation of state of the dark energy model asymptotically tends to the fiducial value of the De Sitter domination epoch, providing an explanation for the accelerated expansion of the Universe at late times, emulating the effect of the cosmological constant. The proposed model has three free parameters, that we constrain using SNIa luminosity distances, along with the CMB shift parameter and the deceleration parameter calculated at the time of dark energy - matter equality. With full knowledge of the best fit for our model, we calculate different observables and compare these predictions with the standard$Λ$CDM model. Besides the general consent of the community with the cosmological constant, there is no fundamental reason to choose that particular candidate as dark energy. Here, we open the opportunity to consider a more dynamical model, that also accounts for the late accelerated expansion of the Universe.

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