论文标题
引力波记忆及其在宇宙学上的尾巴
Gravitational wave memory and its tail in cosmology
论文作者
论文摘要
我们研究了具有物质和宇宙常数的FRW宇宙学模型中的重力波记忆效应。由于背景是弯曲的，重力辐射会在主信号沿着观察者的过去光锥传播的主要信号下形成尾部部分。首先，我们讨论由二进制系统提出的一阶重力波，并发现尾巴仅根据先前的结果提供可忽略不计的记忆。然后，我们研究来自诱导的引力辐射的非线性记忆效应，这些辐射是通过一阶重力辐射在宇宙学距离上传播的。在诱导的引力波的光锥部分中，我们发现在宇宙学记忆效应的先前研究中错过了一个新的术语。此外，我们表明诱导的引力波有一个尾部部分，该部分在光锥部分通过并在宇宙时间尺度上长到相当大的幅度后慢慢积聚。记忆效应的尾部部分将是随机引力波背景中的新组成部分。
We study gravitational wave memory effect in the FRW cosmological model with matter and cosmological constant. Since the background is curved, gravitational radiation develops a tail part arriving after the main signal that travels along the past light cone of the observer. First we discuss first order gravitational wave sourced by a binary system, and find that the tail only gives a negligible memory, in accord with previous results. Then we study the nonlinear memory effect coming from induced gravitational radiation sourced by first order gravitational radiation propagating over cosmological distances. In the light cone part of the induced gravitational wave we find a novel term missed in previous studies of the cosmological memory effect. Furthermore, we show that the induced gravitational wave has a tail part that slowly accumulates after the light cone part has passed and grows to a sizeable magnitude over a cosmological timescale. This tail part of the memory effect will be a new component in the stochastic gravitational wave background.
