Self-Consistent Evolution of Extreme Mass Ratio Inspirals

我们将研究在超大质量黑洞周围轨道上的紧凑物体的极端质量比螺旋（EMRI），由于引力波的发射，最终陷入超大质量黑洞。 我们将推广现有的方法的基础上的有效源的方法从标量的情况下，更有趣的（和苛刻的）引力的情况下，能够执行完全自洽的粒子轨迹和辐射场的演化的目的。 EMRI有望成为未来天基引力波探测器的主要引力波源。对这些事件的观测可以用来测试黑洞无毛定理，方法是在小型致密物体螺旋进入时绘制出黑洞度量。 然而，一个成功的测试将需要非常准确的预测整个重力波形，在数十万到数百万个轨道周期内具有小的相位误差。缓慢的轨道演化是由粒子与粒子自身产生的扰动的相互作用决定的，即所谓的自作用力。 虽然辐射部分的自作用力是唯一负责的轨道参数的演变，导致振幅和频率的波形的演变，保守的一部分仍然可以影响相位。 目前的方法来计算EMRI波形演变的系统，如果它是从一个测地线到下一个。 轨道参数的变化是从几个轨道上的通量或自作用力本身的平均值计算出来的。 近似方法必须用轨道和引力摄动的完全自洽演化来检验。使用有效的源代码方法，这种自洽的演变现在是触手可及的。这个项目将利用和整合几个互补的NSF项目，专注于开发开源代码和建立跨许多科学领域的研究社区。 在这些社区中，该项目将扩大现有的基础设施和计算方法，使其不仅适用于我们的团队，而且适用于更广泛的自我力量社区。 这项建议的一个核心部分是培养一名研究生。 学生将被整合到路易斯安那州立大学的数值相对论小组和国际自我力量社区。PI Diener参加了LSU的两个REU项目（一个在CCT，一个在物理系），本科生通过CCT的Cactus组开发的简单用户界面，使用真实的生产代码获得计算相对论天体物理学的研究经验。 在未来几年里，REU的研究项目将以该项目为基础。

We will investigate extreme-mass-ratio inspirals (EMRIs) of compact objects in orbit around super-massive black holes that, due to emission of gravitational waves, eventually plunge into the super-massive black hole. We will generalize existing methods based on the effective source approach from the scalar case to the more interesting (and demanding) gravitational case with the aim of being able to perform fully self-consistent evolutions of both the particle trajectory and the radiation field. EMRIs are expected to be a major source of gravitational waves for future space-based gravitational wave detectors. The observation of such events can be used to test the black hole No-Hair Theorem by mapping out the black hole metric as the small compact object spirals in. However, a successful test will require very accurate predictions of the full gravitational waveform with small phase errors over hundreds of thousands to millions of orbital periods. The slow orbital evolution is determined by the interaction of the particle with the perturbations produced by the particle itself, the so called self-force. Though the radiative part of the self-force is solely responsible for the evolution of the orbital parameters resulting in amplitude and frequency evolution of the waveform, the conservative piece can still affect the phase. Current approaches to calculating EMRI waveforms evolve the system as if it were going from one geodesic to the next. The change of the orbital parameters is calculated from averages of fluxes or the self-force itself over several orbits. The approximate methods have to be checked with fully self-consistent evolutions of both the orbit and gravitational perturbations. Using the effective source approach, such self-consistent evolutions are now within reach.This project will leverage and integrate with several complementary NSF projects which focus on developing open-source codes and building research communities across many fields of science. Within these communities, this project will broaden the existing infrastructure and computational methods and make them available not only to our group but to the broader self-force community. A central part of this proposal is the training of a graduate student. The student will be integrated into both the numerical relativity group at LSU and the international self-force community. PI Diener participates in two REU programs at LSU (one at the CCT, one in the physics department)where undergraduates gain research experience in computational relativistic astrophysics using real production code via simple user interfaces developed in the Cactus group at the CCT. In the coming years the REU research projects will be based on this project.