Signatures from Dark Matter Accretion and Superradiance in Black Hole Ringdown

黑洞衰变可能是从引力坍塌事件产生的引力波中提取的最干净的可观测数据之一。它将用线性微扰理论来描述，并具有许多关键特征，使其能够被用作新物理学的探测器。在这个项目中，我们计划从一系列不同的影响来描述对Ring Down的影响。主要的重点将是通过开发一种结合了N体代码和数值相对论代码的数值算法来研究暗物质在黑洞周围吸积的影响。将会有许多技术挑战--如何平滑n体系统的能量密度，如何准确定义初始条件，如何确定相关的时间尺度--但从第一步开始，就应该有可能构建一种研究这种系统的新的工作工具。有了这个工具，人们就可以模拟黑洞周围的暗物质光晕，并寻找潜在的有趣的信号，最值得注意的是这种光晕将对合并和产生的振铃信号产生的影响。第二个重点将是模拟克尔黑洞周围自旋2场的超辐射。研究表明，较高的自旋场比标量场更有效地进入超辐射区域。这意味着可以在计算机上更快地模拟这些系统，并观察超级辐射的开始。一旦证明这是真的，就应该有可能研究双星系统周围可能出现的超辐射及其对合并的反作用。同样，重点将放在这样的过程如何影响振铃。最后，提出从振铃信号中提取信息的准确方法是至关重要的。最后一个重点将是开发可应用于当前和未来数据的方法。

Black hole ring down is, potentially, one of the cleanest observables to be extracted from gravitational wave production from a gravitational collapse event. It is will described in terms of linear perturbation theory and has a number of key features that allow it to be used as a probe of new physics. In this project we plan to characterize the impact on ring down from a range of different effects. The main focus will be on studying the impact of dark matter accretion around a black hole by developing a numerical algorithm that combines an N-body code with a numerical relativity code. There will be a number of technical challenges - how to smooth the energy density of the n-body system, how to accurately define the initial conditions, how to identify the relevant time scales - but, from the first step it should be possible to construct a novel, working tool for studying such systems. With the tool in hand, one can then simulate the dark matter halos around black holes and look for potentially interesting signatures, most notable the impact such halos will have on mergers and the resulting ringdown signal.A second focus will be to model the superradiance from spin 2 fields around a Kerr black hole. It has been shown that higher spin fields enter the super-radiant regime much more efficiently than scalar fields. This means that it should be possible to simulate theses systems much more quickly on a computer and watch the onset of super-radiance. Once this is shown to be true, it should be possible to study the possible onset of super-radiance around binary systems and their backreaction on mergers. Again, the focus will be on how such a process affects ringdown.Finally, it is essential to come up with accurate methods to extract information from the ringdown signal. A final focus will be to develop such methods that can be applied to current and future data.