Theory-agnostic framework for inspiral tests of general relativity with higher-harmonic gravitational waves
Theory-agnostic framework for inspiral tests of general relativity with higher-harmonic gravitational waves
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DOI：
10.1103/physrevd.106.024026
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发表时间：
2022-03
影响因子：
5
通讯作者：
S. Mezzasoma;N. Yunes
中科院分区：
文献类型：
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作者：
S. Mezzasoma;N. Yunes
最近的引力波观测表明存在高次谐波，因此可能表明这些波是在具有不对称质量比的致密物体的螺旋中产生的。具有更高谐波的信号包含大量信息，可以更好地估计系统参数，并可能对广义相对论进行更严格的测试。然而，包含高次谐波的引力波模型仅在广义相对论范围内发展起来，而测试与广义相对论无关的理论偏差的模型则纯粹基于信号的主模式。我们在这里将参数化的后爱因斯坦框架扩展到包括 ℓ = 2 、 3 和 4 高次谐波到第一后牛顿阶，因此提供了一个现成的傅立叶域波形模型，用于测试具有高次谐波的广义相对论。我们发现傅里叶相位的高次谐波的变形可以很容易地映射到主谐波的变形，而傅里叶振幅的高次谐波的变形通常不能以与理论无关的方式映射。尽管如此，我们为波形幅度的变形开发了一个简单的 ansatz（通过时域幅度的重新缩放变形），它既最大限度地减少了独立幅度变形参数的数量，又捕获了迄今为止所有已知修改理论的预测。
Recent gravitational wave observations show evidence for the presence of higher harmonics, thus possibly indicating that these waves were generated in the inspiral of compact objects with asymmetric mass ratios. Signals with higher harmonics contain a trove of information that can lead to a better estimation of system parameters and possibly to more stringent tests of general relativity. Gravitational wave model that include higher harmonics, however, have only been developed within general relativity, while models to test theory-agnostic deviations from general relativity have been purely based on the signal’s dominant mode. We here extend the parameterized post-Einsteinian framework to include the ℓ = 2 , 3 and 4 higher harmonics to first post-Newtonian order, therefore providing a ready-to-use Fourier-domain waveform model for tests of general relativity with higher harmonics. We find that the deformations to the higher harmonics of the Fourier phase can be easily mapped to the deformation of the dominant harmonic, while the deformations to the higher-harmonics of the Fourier amplitude in general cannot in a theory-agnostic way. Nonetheless, we develop a simple ansatz for the deformations of the waveform amplitude (through a re-scaling deformation of the time-domain amplitude) that both minimizes the number of independent amplitude deformations parameters and captures the predictions of all known modified theories to date.