测量暗的速度：探测暗能量扰动
Measuring the Speed of Dark: Detecting Dark Energy Perturbations
摘要：
暗能量的性质不仅可以通过它的状态方程来探测，还可以通过它的微观物理来探测，其特征在于对暗能量密度和压力的扰动的声速。当声速降到光速以下时，暗能量的不均匀性增加，影响到CMB和物质的功率谱。我们表明，当前的数据可以把没有显着的限制值的声速时，暗能量纯粹是一个最近的现象，但可以开始显示更有趣的结果，早期的暗能量模型。例如，当前数据的最佳拟合模型对动力学（w（a）\ne-1）、与quintessence不同的自由度（c_s \ne 1）和暗能量的早期存在（Omega_ de（a<<1）\ne 0）具有轻微偏好。未来的数据可能会通过测量其空间和时间变化来打开一扇关于暗能量的新窗口。
英文摘要：
The nature of dark energy can be probed not only through its equation of state, but also through its microphysics, characterized by the sound speed of perturbations to the dark energy density and pressure. As the sound speed drops below the speed of light, dark energy inhomogeneities increase, affecting both CMB and matter power spectra. We show that current data can put no significant constraints on the value of the sound speed when dark energy is purely a recent phenomenon, but can begin to show more interesting results for early dark energy models. For example, the best fit model for current data has a slight preference for dynamics (w(a)\ne-1), degrees of freedom distinct from quintessence (c_s\ne1), and early presence of dark energy (Omega_ de(a<<1)\ne0). Future data may open a new window on dark energy by measuring its spatial as well as time variation.
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。
