Cosmological perturbations of a perfect fluid and noncommutative variables
Cosmological perturbations of a perfect fluid and noncommutative variables
复制标题
完美流体和非交换变量的宇宙学扰动
DOI：
--
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
T. Suyama
中科院分区：
文献类型：
--
作者：
A. D. Felice;J. Gerard;T. Suyama
我们描述了完美流体在作用水平上的线性宇宙扰动，从而为仅基于运动方程的标准方法提供了替代方案。这种作用不仅适用于具有正压状态方程的完美流体，而且也适用于压力取决于两个热力学变量的流体。通过量化系统，我们发现（1）一些扰动场表现出一种非交换性，与强磁场中运动的带电粒子观察到的非交换性非常相似，（2）局部曲率和压力扰动不能同时测量，（3）如果违反零能量条件，就会出现鬼影。
We describe the linear cosmological perturbations of a perfect fluid at the level of an action, providing thus an alternative to the standard approach based only on the equations of motion. This action is suited not only to perfect fluids with a barotropic equation of state, but also to those for which the pressure depends on two thermodynamical variables. By quantizing the system we find that (1) some perturbation fields exhibit a noncommutativity quite analogous to the one observed for a charged particle moving in a strong magnetic field, (2) local curvature and pressure perturbations cannot be measured simultaneously, (3) ghosts appear if the null energy condition is violated.