The effective theory of quintessence: the w < 1 side unveiled
The effective theory of quintessence: the w < 1 side unveiled
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DOI：
10.1088/1475-7516/2009/02/018
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发表时间：
2008-11
影响因子：
6.4
通讯作者：
P. Creminelli;G. D’Amico;J. Noreña;F. Vernizzi
中科院分区：
文献类型：
--
作者：
P. Creminelli;G. D’Amico;J. Noreña;F. Vernizzi
我们研究了一般的单场暗能量模型，通过对它们围绕给定背景的微扰的最一般理论的参数化，包括更高的导数项。在适当的范围内，这种方法再现了标准的精华、k本质和幽灵凝聚。我们没有发现与状态方程w{subq}-1或跨越幻象分界w{subq}=-1有关的一般病理学。稳定性要求暗能量的w{subq}<；-1面在宇宙学尺度上表现为几乎为零音速的k-本质流体。这意味着，当与具有w{subq}<；-1或跨越幻影分水岭的数据模型进行比较时，应将声速设置为零。我们总结了经典平面(1+w{subq})对声速平方的理论约束和稳定性约束。
We study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard quintessence, k-essence and ghost condensation. We find no general pathology associated to an equation of state w{sub Q} < -1 or in crossing the phantom divide w{sub Q} = -1. Stability requires that the w{sub Q} < -1 side of dark energy behaves, on cosmological scales, as a k-essence fluid with a virtually zero speed of sound. This implies that one should set the speed of sound to zero when comparing with data models with w{sub Q} < -1 or crossing the phantom divide. We summarize the theoretical and stability constraints on the quintessential plane (1+w{sub Q}) vs. speed of sound squared.