迈向超越广义相对论的双黑洞长且精确的数值相对论波形
Towards long and accurate numerical relativity waveforms of binary black holes beyond general relativity
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中文总结 AI 辅助
该研究结合谱方法与“方程固定”方法，生成超越广义相对论的双黑洞长且精确的数值相对论波形，为引力波检验及替代理论波形模型校准提供关键基础。
中文摘要 AI 辅助
超越广义相对论（GR）的理论中致密双星的数值相对论（NR）模拟，对未来利用引力波（GW）检验引力的持续发展至关重要。在这篇通讯中，我们证明谱方法与“方程固定”方法的结合，可生成文献中真实超越GR理论的最长波形，从而让替代引力理论的NR方法更接近GR领域的先进水平。为具体说明，我们聚焦于广为人知的标量高斯-博内引力的位移对称版本，该理论假设存在额外的动力学标量场，且描述的黑洞（BHs）不同于克尔解。我们提取了等质量、无自旋、偏心度降低的双黑洞在未来类光无穷远处的引力波与标量波形，并量化得出40个以上引力波周期（20个以上轨道）后的相位误差≤1弧度。我们还表明，该替代理论中的引力波相位修正可与爱因斯坦理论区分，且并合时间早于GR。获取此类波形是与后牛顿理论进行精确比较、校准超越GR的波形模型的垫脚石。
英文摘要
Numerical relativity (NR) simulations of compact binaries in theories beyond general relativity (GR) will be pivotal for the continued development of future tests of gravity with gravitational waves (GWs). In this Letter, we show that the combination of spectral methods and the "fixing-the-equations" approach allows us to produce the longest waveforms in the literature for a genuine beyond-GR theory, thus bringing NR methods for alternative theories of gravity closer to the state-of-the-art in GR. For concreteness, we focus on the well-known shift-symmetric version of scalar Gauss-Bonnet gravity, a theory postulating the existence of an additional dynamical scalar and describing black holes (BHs) different from the Kerr solution. We extract the gravitational and scalar waveforms at future null infinity for equal-mass, nonspinning, eccentricity-reduced BH binaries, and quantify the phase errors to be $\lesssim$ 1 rad after 40+ GW cycles (20+ orbits). We also show that the GW phase corrections in this alternative theory are distinguishable from Einstein's theory and lead to an earlier coalescence time than in GR. Obtaining such waveforms is a stepping stone to perform precise comparisons with Post-Newtonian theory and to calibrate waveform models beyond GR.
