We consider cosmological models where dark energy is described by a dynamical field equipped with the Chameleon screening mechanism, which serves to hide its effects in local dense regions and to conform to Solar System observations. In these models, there is no universal gravitational coupling and here we study the effective couplings that determine the force between massive objects, $G_N$, and the propagation of gravitational waves, $G_{gw}$. In particular, we revisit the Chameleon screening mechanism without neglecting the time dependence of the galactic environment where local regions are embedded in, and analyze the induced time evolution on $G_N$ and $G_{gw}$, which can be tested with Lunar Laser Ranging and direct gravitational waves observations. We explicitly show how and why these two couplings generically differ. We also find that due to the particular way the Chameleon screening mechanism works, their time evolutions are highly suppressed in the weak-field non-relativistic approximation.

中文翻译：

---

变色龙模型中的引力耦合

我们考虑宇宙学模型，其中暗能量由配备变色龙筛选机制的动力学场描述，该机制用于隐藏其在局部密集区域的影响并符合太阳系观测。在这些模型中，没有普遍的引力耦合，在这里我们研究确定大质量物体之间的力 $G_N$ 和引力波传播 $G_{gw}$ 的有效耦合。特别是，我们在不忽略局部区域嵌入的银河环境的时间依赖性的情况下重新审视了变色龙筛选机制，并分析了 $G_N$ 和 $G_{gw}$ 上的诱导时间演化，这可以用 Lunar Laser 进行测试测距和直接引力波观测。我们明确地展示了这两种耦合通常不同的方式和原因。