Crossing the phantom divide with parametrized post-Friedmann dark energy
Crossing the phantom divide with parametrized post-Friedmann dark energy
复制标题
DOI：
10.1103/physrevd.78.087303
复制
发表时间：
2008-08
影响因子：
5
通讯作者：
Wenjuan Fang;Wayne Hu;A. Lewis
中科院分区：
文献类型：
--
作者：
Wenjuan Fang;Wayne Hu;A. Lewis
具有单一标量场的暗能量模型不能跨越由宇宙学常数设定的状态方程。允许交叉的更一般的模型需要额外的自由度来确保重力稳定性。我们表明，宇宙加速的参数化后弗里德曼描述提供了一个简单而准确的描述多个标量场交叉模型。此外，处方提供了一个很好的控制的近似范围广泛的光滑暗能量模型。它保存了能量和动量，并且在尺度上的度量演化是精确的，远远高于和低于相对平滑的过渡尺度。标准的线性微扰工具已经被修改，以包括这一描述，并公开提供用于研究暗能量，涉及到视界尺度的宇宙结构。
Dark energy models with a single scalar field cannot cross the equation of state divide set by a cosmological constant. More general models that allow crossing require additional degrees of freedom to ensure gravitational stability. We show that a parameterized post-Friedmann description of cosmic accelerzation provides a simple but accurate description of multiple scalar field crossing models. Moreover the prescription provides a well-controlled approximation for a wide range of smooth dark energy models. It conserves energy and momentum and is exact in the metric evolution on scales well above and below the transition scale to relative smoothness. Standard linear perturbation tools have been altered to include this description and made publicly available for studies of the dark energy involving cosmological structure out to the horizon scale.