Gravitational waveforms from the inspiral of compact binaries in the Brans-Dicke theory in an expanding Universe
Gravitational waveforms from the inspiral of compact binaries in the Brans-Dicke theory in an expanding Universe
复制标题
DOI：
10.1103/physrevd.108.024006
复制
发表时间：
2022-05
影响因子：
5
通讯作者：
Tan Liu;Yan Wang;Wen Zhao
中科院分区：
文献类型：
--
作者：
Tan Liu;Yan Wang;Wen Zhao
在修正的引力理论中，如Brans-Dicke理论，宇宙的背景演化和周围的扰动与广义相对论不同。因此，这些理论中用于研究标准海妖的重力波形应该被修改。波形的修改可以分为两类：波生成效应和波传播效应。目前，修正引力理论中用于研究标准海妖的波形只考虑了波的传播效应，而忽略了波的产生效应;而后牛顿理论中着重研究波的产生效应的波形则没有考虑波的传播效应，不能直接应用于标准海妖研究中红移不可忽略的源。在这项工作中，我们构造了一致的波形的标准海笛在Brans-Dicke理论。波的产生效应包括标量呼吸极化$h_B$的发射以及对张量极化$h_+$和$h_\times$的修正;波的传播效应是引力波形的光度距离的修正。利用一致波形，我们分析了由于忽略波的产生效应而导致的参数估计偏差。考虑到爱因斯坦望远镜的观测，我们发现红移啁啾质量的理论偏差与统计误差之比源距的理论偏差与统计误差之比大两个数量级。对于像GW 191219这样的黑洞-中子星星双星系统，红移啁啾质量的理论偏差可以比统计误差大几倍。
In modified gravity theories, such as the Brans-Dicke theory, the background evolution of the Universe and the perturbation around it are different from that in general relativity. Therefore, the gravitational waveforms used to study standard sirens in these theories should be modified. The modifications of the waveforms can be classified into two categories: wave generation effects and wave propagation effects. Hitherto, the waveforms used to study standard sirens in the modified gravity theories incorporate only the wave propagation effects and ignore the wave generation effects; while the waveforms focusing on the wave generation effects, such as the post-Newtonian waveforms, do not incorporate the wave propagation effects and cannot be directly applied to the sources with non-negligible redshifts in the study of standard sirens. In this work, we construct the consistent waveforms for standard sirens in the Brans-Dicke theory. The wave generation effects include the emission of the scalar breathing polarization $h_b$ and the corrections to the tensor polarizations $h_+$ and $h_\times$; the wave propagation effect is the modification of the luminosity distance for the gravitational waveforms. Using the consistent waveforms, we analyze the parameter estimation biases due to the ignorance of the wave generation effects. Considering the observations by the Einstein Telescope, we find that the ratio of the theoretical bias to the statistical error of the redshifted chirp mass is two orders of magnitude larger than that of the source distance. For black hole-neutron star binary systems like GW191219, the theoretical bias of the redshifted chirp mass can be several times larger than the statistical error.