Dark energy, α-attractors, and large-scale structure surveys
Dark energy, α-attractors, and large-scale structure surveys
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DOI：
10.1088/1475-7516/2018/06/041
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发表时间：
2017-12
影响因子：
6.4
通讯作者：
Yashar Akrami;R. Kallosh;Andrei Linde;V. Vardanyan
中科院分区：
文献类型：
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作者：
Yashar Akrami;R. Kallosh;Andrei Linde;V. Vardanyan
在过去的几年里，已经发现了一个大家族的宇宙吸引子模型，它可以成功地匹配最新的与暴胀相关的观测数据。这些模型中的许多也可以描述一个小的宇宙学常数Λ，这提供了对宇宙学加速的当前阶段的最自然的描述。本文研究了包含宇宙学常数Λ作为自由参数的具有动力学暗能量的α-吸引子模型。主要地，0Λ >的模型收敛到状态方程w=−1的渐近状态。然而，也有一些模型的w≠-1，这与当前的观测结果是兼容的。在最简单的Λ = 0的模型中，张量与标量之比r=12α/N2，渐近状态方程w=−1+2/9α（通常与当前值不同）。例如，在α = 7/3的七圆盘M理论相关模型中，我们发现r = 10−2，渐近状态方程为w = −0.9。未来的观测，包括大规模的结构调查以及B模式探测器将测试这些，以及这里提出的更一般的模型。我们还讨论了典型暴胀模型中的引力再加热，并认为从暴胀宇宙学的角度来看，对它的研究可能很有趣。这样的模型需要更多的e折叠，因此预测的光谱指数ns可以超过更传统的模型中的值约0.006。这表明了一种区分传统暴胀模型和典型暴胀模型的方法，即使它们预测w =-1。
Over the last few years, a large family of cosmological attractor models has been discovered, which can successfully match the latest inflation-related observational data. Many of these models can also describe a small cosmological constant Λ, which provides the most natural description of the present stage of the cosmological acceleration. In this paper, we study α-attractor models with dynamical dark energy, including the cosmological constant Λ as a free parameter. Predominantly, the models with 0Λ > converge to the asymptotic regime with the equation of state w=−1. However, there are some models with w≠ −1, which are compatible with the current observations. In the simplest models with Λ = 0, one has the tensor to scalar ratio r=12α/N2 and the asymptotic equation of state w=−1+2/9α (which in general differs from its present value). For example, in the seven disk M-theory related model with α = 7/3 one finds r ∼ 10−2 and the asymptotic equation of state is w ∼ −0.9. Future observations, including large-scale structure surveys as well as B-mode detectors will test these, as well as more general models presented here. We also discuss gravitational reheating in models of quintessential inflation and argue that its investigation may be interesting from the point of view of inflationary cosmology. Such models require a much greater number of e-folds, and therefore predict a spectral index ns that can exceed the value in more conventional models by about 0.006. This suggests a way to distinguish the conventional inflationary models from the models of quintessential inflation, even if they predict w = −1.