Hagala R, Llinares C, Mota D F
Institute of Theoretical Astrophysics, University of Oslo, PO Box 1029 Blindern, 0315 Oslo, Norway.
Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE, United Kingdom.
Phys Rev Lett. 2017 Mar 10;118(10):101301. doi: 10.1103/PhysRevLett.118.101301.
Extending general relativity by adding extra degrees of freedom is a popular approach for explaining the accelerated expansion of the Universe and to build high energy completions of the theory of gravity. The presence of such new degrees of freedom is, however, tightly constrained from several observations and experiments that aim to test general relativity in a wide range of scales. The viability of a given modified theory of gravity, therefore, strongly depends on the existence of a screening mechanism that suppresses the extra degrees of freedom. We perform simulations, and find that waves propagating in the new degrees of freedom can significantly impact the efficiency of some screening mechanisms, thereby threatening the viability of these modified gravity theories. Specifically, we show that the waves produced in the symmetron model can increase the amplitude of the fifth force and the parametrized post Newtonian parameters by several orders of magnitude.
通过添加额外自由度来扩展广义相对论是解释宇宙加速膨胀以及构建引力理论的高能完备形式的一种流行方法。然而，这些新自由度的存在受到了旨在在广泛尺度上检验广义相对论的多项观测和实验的严格限制。因此，给定的修正引力理论的可行性在很大程度上取决于一种抑制额外自由度的屏蔽机制的存在。我们进行了模拟，发现新自由度中传播的波会显著影响某些屏蔽机制的效率，从而威胁到这些修正引力理论的可行性。具体而言，我们表明在对称子模型中产生的波可以将第五种力的幅度和参数化后牛顿参数提高几个数量级。
