论文标题
频域自我计算的倍曲面方法
Hyperboloidal method for frequency-domain self-force calculations
论文作者
论文摘要
引力自力理论是对小质量比率紧凑型二进制产生引力波发射的主要方法。该方法在质量比的范围内扰动地扩展了二元的度量。扰动的来源取决于轨道构型,计算方法和扰动扩展的顺序。这些来源分为三个范围:(i)分布,(ii)WorldTube和(iii)无限的支持。尤其是后者对于新兴的二阶(以质量比)计算很重要。传统的频域方法采用了参数方法的变化,并计算出具有数值边界条件的标准时间切片的扰动,该条件在有限半径下从渐近行为的串联膨胀中提供。这种方法非常成功,但是边界条件的计算很乏味,并且该方法不太适合于在所有半径上必须计算均匀溶液的无限源。这项工作开发了一种替代方法,其中倍boloid骨切片会叶落下时空,而压实的坐标简化了边界处理。我们使用具有分析网格细化的多域光谱求解器实现这种方法,并在Schwarzschild Black Hole周围的圆形轨道上使用标量场自力作为示例问题。该方法适用于自我计算中遇到的所有三个源类,并且在传统方法中具有明显的优势。例如,我们的代码有效地计算具有极大轨道半径($ r_ {p}> 10^5M $)的轨道的扰动或具有很高球形谐波模式索引($ \ ell \ ell \ ge 100 $)的模式。我们的结果表明,倍曲面方法可以在自我计算中起重要作用。
Gravitational self-force theory is the leading approach for modeling gravitational wave emission from small mass-ratio compact binaries. This method perturbatively expands the metric of the binary in powers of the mass ratio. The source for the perturbations depends on the orbital configuration, calculational approach, and the order of the perturbative expansion. These sources fall into three broad classes: (i) distributional, (ii) worldtube, and (iii) unbounded support. The latter, in particular, is important for emerging second-order (in the mass ratio) calculations. Traditional frequency domain approaches employ the variation of parameters method and compute the perturbation on standard time slices with numerical boundary conditions supplied at finite radius from series expansions of the asymptotic behavior. This approach has been very successful, but the boundary conditions calculations are tedious, and the approach is not well suited to unbounded sources where homogeneous solutions must be computed at all radii. This work develops an alternative approach where hyperboloidal slices foliate the spacetime, and compactifying coordinates simplify the boundary treatment. We implement this approach with a multi-domain spectral solver with analytic mesh refinement and use the scalar-field self-force on circular orbits around a Schwarzschild black hole as an example problem. The method works efficiently for all three source classes encountered in self-force calculations and has distinct advantages over the traditional approach. For example, our code efficiently computes the perturbation for orbits with extremely large orbital radii ($r_{p}>10^5M$) or modes with very high spherical harmonic mode index ($\ell \ge 100$). Our results indicate that hyperboloidal methods can play an essential role in self-force calculations.