论文标题
标量调整理论中的宇宙记忆效应
Cosmological memory effect in scalar-tensor theories
论文作者
论文摘要
宇宙记忆效应是由于引力波的通过，位于FLRW时空中的测试颗粒的相对分离的永久变化。如果在空间平坦的FLRW时空中充满了总体相对论中完美的流体，则众所周知，只有张量扰动会导致记忆效应，而标量和矢量扰动则没有。在本文中，我们表明，在标量调整理论的背景下，与标量重力相关的标量扰动也有助于记忆效应。我们发现，根据质量和耦合，宇宙膨胀对标量扰动引起的记忆效应的影响可能比张量扰动引起的影响更强或更弱。作为副产品，在附录中，我们开发了一个通用框架，该框架可用于研究任何弯曲的时空区域中的耦合波方程，该区域通过时间切片接受叶面。
The cosmological memory effect is a permanent change in the relative separation of test particles located in a FLRW spacetime due to the passage of gravitational waves. In the case of a spatially flat FLRW spacetime filled with a perfect fluid in general relativity, it is known that only tensor perturbations contribute to the memory effect while scalar and vector perturbations do not. In this paper, we show that in the context of scalar-tensor theories, the scalar perturbations associated to the scalar graviton contribute to the memory effect as well. We find that, depending on the mass and coupling, the influence of cosmic expansion on the memory effect due to the scalar perturbations can be either stronger or weaker than the one induced by the tensor perturbations. As a byproduct, in an appendix, we develop a general framework which can be used to study coupled wave equations in any curved spacetime region which admits a foliation by time slices.
