论文标题
在非局部重力中重新访问标量和张量扰动
Revisiting scalar and tensor perturbations in a nonlocal gravity
论文作者
论文摘要
非局部RT重力是一种成功的修饰重力理论，不仅解释了延迟宇宙加速度，而且在太阳系中的行为也很好。以前的分析通常假设辅助场$ s_i $在宇宙背景下消失。但是，我们发现背景$ s_i $随着宇宙的扩展与$ a^2 $成正比。然后，我们讨论非零背景$ s_i $对宇宙背景演变，标量和张量扰动的影响。我们发现宇宙背景演变独立于$ s_i $，而非零背景$ s_i $对太阳系量表处弱场限制的影响可以忽略不计。对于张量扰动，我们发现唯一可能的可观察效果是非零背景$ s_i $对Ligo重力波振幅以及光度距离的影响。未来的高红移引力波观测可用于约束$ s_i $的背景值。
Nonlocal RT gravity is a successful modified gravity theory, which not only explains the late-time cosmic acceleration but also behaves well in the solar system. Previous analysis generally assumes the auxiliary field $S_i$ vanishes at the cosmic background. However, we find the background $S_i$ is proportional to $a^2$ with the expansion of the universe. Then we discuss the influence of the nonzero background $S_i$ on the cosmic background evolution, the scalar and tensor perturbations. We find the cosmic background evolution is independent of $S_i$, and the influence of the nonzero background $S_i$ on the weak field limit at solar system scales is negligible. For the tensor perturbation, we find the only possible observable effect is the influence of nonzero background $S_i$ on the LIGO gravitational wave amplitude and also luminosity distance. Future high redshift gravitational wave observations could be used to constrain the background value of $S_i$.
