Institute for Theoretical Astrophysics, University of Oslo, N-0315 Oslo, Norway.
Phys Rev Lett. 2012 Dec 14;109(24):241102. doi: 10.1103/PhysRevLett.109.241102. Epub 2012 Dec 10.
It is shown that extensions to general relativity, which introduce a strongly coupled scalar field, can be viable if the interaction has a nonconformal form. Such disformal coupling depends upon the gradients of the scalar field. Thus, if the field is locally static and smooth, the coupling becomes invisible in the Solar System: this is the disformal screening mechanism. A cosmological model is considered where the disformal coupling triggers the onset of accelerated expansion after a scaling matter era, giving a good fit to a wide range of background observational data. Moreover, the interaction leaves signatures in the formation of large-scale structure that can be used to probe such couplings.
研究表明，如果引入的相互作用具有非共形形式，则广义相对论的扩展是可行的。这种非共形耦合取决于标量场的梯度。因此，如果场是局部静态和光滑的，那么在太阳系中，耦合将变得不可见：这就是非共形屏蔽机制。考虑了一个宇宙学模型，其中非共形耦合在标量时代的缩放之后引发了加速膨胀的开始，从而很好地拟合了广泛的背景观测数据。此外，相互作用在大尺度结构的形成中留下了特征，可以用来探测这种相互作用。
