Dynamical analysis of screening in scalar-tensor theory
Dynamical analysis of screening in scalar-tensor theory
复制标题
标量张量理论中筛选的动力学分析
DOI：
10.1103/physrevd.103.024009
复制
发表时间：
2021
影响因子：
5
通讯作者：
Yoo Chul-Moon
中科院分区：
文献类型：
--
作者：
Nakamura Tomohiro;Ikeda Taishi;Saito Ryo;Tanahashi Norihiro;Yoo Chul-Moon
我们研究了标量张量理论中静态位形上球对称扰动的线性和非线性动力学，重点是变色龙屏蔽机制。我们特别解决两个问题：有多少的扰动可以源的第五个力时，静态背景是很好的屏蔽，以及所产生的第五个力是否可以改变的稳定性和结构的背景配置。对于线性微扰，我们利用绝热近似得到了傅里叶模频率平方的下界。如果这个下界是负的，可能会有不稳定的模式，我们发现，不稳定的条件可以改变的第五个力，虽然这种影响是由屏蔽参数抑制。对于非线性扰动，因为我们主要感兴趣的是短波长模式的第五力可能会变得更强，我们进行了平面近似下的数值模拟。对于一个足够大的初始振幅的密度扰动，我们发现，第五力的大小可以与牛顿引力，即使当模型参数的选择，使静态背景是很好的筛选。它还表明，如果筛选是有效的静态背景下，流体动力学主要是由压力梯度，并没有显着的第五力的影响。
We investigate linear and nonlinear dynamics of spherically symmetric perturbations on a static configuration in scalar-tensor theories focusing on the chameleon screening mechanism. We particularly address two questions: how much the perturbations can source the fifth force when the static background is well screened, and whether the resultant fifth force can change the stability and structure of the background configuration. For linear perturbations, we derive a lower bound for the square of the Fourier mode frequencyusing the adiabatic approximation. There may be unstable modes if this lower bound is negative, and we find that the condition of the instability can be changed by the fifth force although this effect is suppressed by the screening parameter. For nonlinear perturbations, because we are mainly interested in short wavelength modes for which the fifth force may become stronger, we perform numerical simulations under the planar approximation. For a sufficiently large initial amplitude of the density perturbation, we find that the magnitude of the fifth force can be comparable to that of Newtonian gravity even when the model parameters are chosen so that the static background is well screened. It is also shown that if the screening is effective for the static background, the fluid dynamics is mostly governed by the pressure gradient and is not significantly affected by the fifth force.