Observables and unobservables in dark energy cosmologies
Observables and unobservables in dark energy cosmologies
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DOI：
10.1103/physrevd.87.023501
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发表时间：
2012-10
影响因子：
5
通讯作者：
L. Amendola;M. Kunz;M. Motta;I. Saltas;I. Sawicki
中科院分区：
文献类型：
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作者：
L. Amendola;M. Kunz;M. Motta;I. Saltas;I. Sawicki
这篇论文的目的是回答以下两个问题：(1)给定对膨胀历史的宇宙学观测和在一系列红移和标度范围内的线性微扰，实际上可以在不施加任何参数化的情况下重建暗能量的哪些性质？(2)这些观测数据是否足以排除只有一个特定的暗能量模型，而是包括单个标量场的整个一般类型的可行模型？这份报告既有好消息，也有坏消息。一方面，我们发现重建暗能量模型的目标从根本上受到物质密度欧米茄_M0、微扰归一化σ_8和当前物质功率谱现值的不可观测性的限制。另一方面，我们发现，在某些条件下，宇宙学观测仍然可以排除整类最一般的单标量场模型，即基于Horndeski拉格朗日的模型。
The aim of this paper is to answer the following two questions: (1) Given cosmological observations of the expansion history and linear perturbations in a range of redshifts and scales as precise as is required, which of the properties of dark energy could actually be reconstructed without imposing any parameterization? (2) Are these observables sufficient to rule out not just a particular dark energy model, but the entire general class of viable models comprising a single scalar field? This paper bears both good and bad news. On one hand, we find that the goal of reconstructing dark energy models is fundamentally limited by the unobservability of the present values of the matter density Omega_m0, the perturbation normalization sigma_8 as well as the present matter power spectrum. On the other, we find that, under certain conditions, cosmological observations can nonetheless rule out the entire class of the most general single scalar-field models, i.e. those based on the Horndeski Lagrangian.