论文标题
重力波泄漏到DGP模型中的额外维度
Leakage of gravitational waves into an extra dimension in the DGP model
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
In the DGP model, the graviton is unstable, which leads to a modification of gravity at cosmological distances. In particular, this leads to the leakage of gravitational waves from the brane into an extra dimension at large distances from the source. However, the calculation of the gravitational wave leakage intensity is a non-trivial task due to the violation of the Huygens principle in the five-dimensional bulk of the DGP setup. The odd dimension of the bulk makes it difficult to extract the radiated part of the field. In this paper, we consider a simplified problem of scalar radiation from a point charge localized on a brane in the framework of the scalar field analog of the DGP model. In this model, the scalar field on the brane can be represented as a continuous spectrum of Kaluza-Klein massive modes. To extract the emitted part of such a field, we generalize the Rohrlich-Teitelboim approach to radiation to the case of a massive four-dimensional field, using its connections to massless fields in four and five dimensions. In the case of a charge moving along a circular trajectory, we obtain the dependence of the radiation energy flux through a 2-sphere localized on the brane on the sphere radius, which provides the intensity of leakage of scalar radiation from the brane. Consistent with the infrared transparency of the bulk, the leakage intensity is found to be higher for low frequency signals. We are also analyzing the possibility of detecting this leak by current and future gravitational-wave observatories.
