LISA中偏心旋近双星的广义相对论参数化检验
A parametrized test of general relativity for inspiralling eccentric binaries in LISA
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中文总结 AI 辅助
本文针对LISA观测的偏心旋近黑洞双星，构建两种含偏差参数δα的频域偏心波形模型，经lisabeta的贝叶斯分析表明，LISA可对δα施加严格约束，且偏心率增大可强化该约束。
中文摘要 AI 辅助
空间探测器激光干涉空间天线（LISA）将观测毫赫兹波段的旋近黑洞双星，其中许多可能保留轨道偏心率。与准圆轨道双星不同，偏心系统通过多个轨道谐波辐射，而相对论近星点进动会在波形中引入长期相位结构。我们利用该结构开发了针对偏心束缚轨道的广义相对论（GR）参数化检验方法。我们构建了频域偏心波形模型，其中唯象偏差参数δα修正广义相对论对保守方位角-径向频率比的预测，δα=0对应广义相对论。我们考虑两种该形变的参数化方式：第一种中，δα仅修正波形中显式依赖进动的边带结构；第二种中，长期进动相位被分配给主导的低阶角载波并以重求和形式保留，后者产生强得多的响应，因为主导波形分量相干累积修正后的相位。我们在lisabeta中实现两种模型，并执行包含时间和频率依赖的LISA响应及相关时延干涉测量可观测值的贝叶斯分析。我们发现LISA可对参数化偏差施加严格约束：对于啁啾质量3000M⊙、初始偏心率e0=0.5的双星，以50的信噪比观测四年，第二种模型给出90%可信区间|δ α|≲10^−4；进一步增大偏心率会引入额外谐波结构并降低双星参数间的简并度，从而强化约束。本文开发的框架具有通用性，可扩展至更完整的偏心波形模型。
英文摘要
The space-based detector Laser Interferometer Space Antenna (LISA) will observe inspiralling black hole binaries in the mHz band, many of which may retain orbital eccentricity. In contrast to quasicircular binaries, eccentric systems radiate through multiple orbital harmonics, while relativistic periastron precession introduces a secular phase structure in the waveform. We exploit this structure to develop a parametrized test of general relativity (GR) for eccentric bound orbits. We construct a frequency-domain eccentric waveform model in which a phenomenological deviation parameter $δα$ modifies the GR prediction for the conservative azimuthal-to-radial frequency ratio, with $δα=0$ corresponding to GR. We consider two parametrizations of this deformation. In the first, $δα$ modifies only the explicit precession-dependent sideband structures of the waveform. In the second, the secular precession phase is assigned to the dominant lower-order angular carriers and retained in resummed form. The latter produces a substantially stronger response because the dominant waveform components coherently accumulate the modified phase. We implement both models within \textsc{lisabeta} and perform a Bayesian analysis including the time- and frequency-dependent LISA response and associated time-delay-interferometry observables. We find that LISA can place stringent constraints on the parametrized deviation. For a binary with chirp mass $3000 M_{\odot}$, initial eccentricity $e_0=0.5$ observed for four years at an SNR of $50$, the second model yields a $90\%$ credible bound of $|δα|\lesssim 10^{-4}$. Increasing eccentricity further sharpens the constraints by introducing additional harmonic structure and reducing degeneracies among the binary parameters. The framework developed here is general and can be extended to more complete eccentric waveform models.
