Berkeley Center for Cosmological Physics and Berkeley Laboratory, University of California, Berkeley, CA 94720, USA.
Philos Trans A Math Phys Eng Sci. 2011 Dec 28;369(1957):4985-97. doi: 10.1098/rsta.2011.0288.
Gravitation governs the expansion and fate of the universe, and the growth of large-scale structure within it, but has not been tested in detail on these cosmic scales. The observed acceleration of the expansion may provide signs of gravitational laws beyond general relativity (GR). Since the form of any such extension is not clear, from either theory or data, we adopt a model-independent approach to parametrizing deviations to the Einstein framework. We explore the phase space dynamics of two key post-GR functions and derive a classification scheme, and an absolute criterion on accuracy necessary for distinguishing classes of gravity models. Future surveys will be able to constrain the post-GR functions' amplitudes and forms to the required precision, and hence reveal new aspects of gravitation.
引力支配着宇宙的膨胀和命运，以及其中大规模结构的增长，但在这些宇宙尺度上尚未得到详细检验。观测到的宇宙膨胀加速可能提供了超越广义相对论（GR）的引力定律的迹象。由于任何此类扩展的形式都不清楚，无论是从理论还是数据来看，我们采用了一种独立于模型的方法来参数化对爱因斯坦框架的偏离。我们探索了两个关键的后 GR 函数的相空间动力学，并推导出了一个分类方案，以及一个区分引力模型类别的绝对精度准则。未来的观测将能够以所需的精度约束后 GR 函数的幅度和形式，并因此揭示引力的新方面。
