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arXiv 2212.06166astro-ph.HEgr-qc
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利用机器学习快速确定 LISA 对极端质量比旋近的灵敏度

Rapid determination of LISA sensitivity to extreme mass ratio inspirals with machine learning

Christian E. A. Chapman-Bird, Christopher P. L. Berry, Graham Woan

AI总结:

本文提出由神经网络插值器和选择函数学习网络组成的快速框架,用于估计 LISA 对 EMRI 的探测选择效应,并在天体物理族群模型中校正偏差、量化关键参数测量精度。

摘要:

对恒星质量致密天体旋近大质量黑洞(MBH)的引力波观测,即极端质量比旋近(EMRI),使我们能够精确测量 MBH 质量和自旋等参数。激光干涉空间天线(Laser Interferometer Space Antenna,LISA)预计将探测到足够多的 EMRI,从而探究其背后的源族群,检验关于 MBH 形成、演化及其环境的理论。族群研究会受到在 EMRI 参数空间中变化的选择效应影响;若不加考虑,这些效应会使推断结果产生偏差。这种偏差可以被校正,但评估大量 EMRI 信号的可探测性在计算上非常昂贵。我们通过以下方式降低这一成本:(i)构建一个快速且准确的神经网络插值器,能够根据 EMRI 的参数预测其信噪比;(ii)利用一个学习选择函数的神经网络进一步加速可探测性估计,并借助第一个神经网络生成数据。由此得到的框架可快速估计选择函数,从而在族群推断分析中完整处理 EMRI 的可探测性。我们将该方法应用于一个具有天体物理动机的 EMRI 族群模型,展示了潜在的选择偏差并随后对其进行校正。在考虑选择效应后,我们预测,利用红移 z=6 以下的 EMRI,LISA 将以 8.8% 的精度测量 MBH 质量函数斜率,以 4.6% 的精度测量致密天体(CO)质量函数斜率,以 10% 的精度测量 MBH 自旋大小分布的宽度,并以 12% 的精度测量事件率。

英文摘要:

Gravitational wave observations of the inspiral of stellar-mass compact objects into massive black holes (MBHs), extreme mass ratio inspirals (EMRIs), enable precision measurements of parameters such as the MBH mass and spin. The Laser Interferometer Space Antenna is expected to detect sufficient EMRIs to probe the underlying source population, testing theories of the formation and evolution of MBHs and their environments. Population studies are subject to selection effects that vary across the EMRI parameter space, which bias inference results if unaccounted for. This bias can be corrected, but evaluating the detectability of many EMRI signals is computationally expensive. We mitigate this cost by (i) constructing a rapid and accurate neural network interpolator capable of predicting the signal-to-noise ratio of an EMRI from its parameters, and (ii) further accelerating detectability estimation with a neural network that learns the selection function, leveraging our first neural network for data generation. The resulting framework rapidly estimates the selection function, enabling a full treatment of EMRI detectability in population inference analyses. We apply our method to an astrophysically motivated EMRI population model, demonstrating the potential selection biases and subsequently correcting for them. Accounting for selection effects, we predict that LISA will measure the MBH mass function slope to a precision of 8.8%, the CO mass function slope to a precision of 4.6%, the width of the MBH spin magnitude distribution to a precision of 10% and the event rate to a precision of 12% with EMRIs at redshifts below z=6.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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