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arXiv 1902.09423astro-ph.CO
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根据最新数据重建暗能量状态方程:理论先验的影响

Reconstruction of the Dark Energy equation of state from latest data: the impact of theoretical priors

Francesca Gerardi, Matteo Martinelli, Alessandra Silvestri

摘要:

我们重建状态方程的暗能量(EoS)从目前的数据使用非参数的方法,而不是假设一个特定的时间演化的这个功能,我们在时间上的bin。我们用两种不同的方法,即平滑阶跃函数和高斯过程重建,来处理仓之间的过渡,调查这两种方法是否会导致兼容的结果。此外,我们包括在重建过程中的EoS的值之间的相关性在不同的时间在一个理论先验的形式,考虑到一组可行性和稳定性的要求,可以施加在替代$Λ$ CDM的模型。在这种情况下,我们必须专注于广泛的,但特定类别的替代模型,即Quintessence和Horndeski引力。我们使用来自CMB,超新星和BAO调查的数据。我们发现使用的不同重建方法之间的总体协议,与这两种方法,我们发现重建的平均值的时间依赖性,不同的趋势取决于研究的模型类。由$Λ$ CDM模型预测的恒定EoS无论如何都落在我们分析的$1σ$范围内。

英文摘要:

We reconstruct the Equation of State of Dark Energy (EoS) from current data using a non-parametric approach where, rather than assuming a specific time evolution of this function, we bin it in time. We treat the transition between the bins with two different methods, i.e. a smoothed step function and a Gaussian Process reconstruction, investigating whether or not the two approaches lead to compatible results. Additionally, we include in the reconstruction procedure a correlation between the values of the EoS at different times in the form of a theoretical prior that takes into account a set of viability and stability requirements that one can impose on models alternative to $Λ$CDM. In such case, we necessarily specialize to broad, but specific classes of alternative models, i.e. Quintessence and Horndeski gravity. We use data coming from CMB, Supernovae and BAO surveys. We find an overall agreement between the different reconstruction methods used; with both approaches, we find a time dependence of the mean of the reconstruction, with different trends depending on the class of model studied. The constant EoS predicted by the $Λ$CDM model falls anyway within the $1σ$ bounds of our analysis.

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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