Probing fundamental fields in strong gravity

目的：开发暗物质环境中黑洞（BH）和黑洞双星（BHB）的数值相对论模拟和分析模型，比较和对比高质量和低质量候选者，并确定每种情况下的观测特征。背景：2015年LIGO对引力波（GW）的探测是科学的一个突破性时刻。LIGO（和Virgo）目前正在进行第三次观测，到目前为止报告了30多个新的候选事件，未来十年将有大量新数据被全球GW仪器网络检测到。这也将是准备丽莎空间使命的关键阶段，它将把我们的视野扩展到探测超大质量黑洞（SMBH）丰富的DM环境和早期宇宙背景信号（~ 10-4 - 10-1 Hz）的频率。为了理解我们将接收到的数据流，我们需要完全理解当前理论（如广义相对论）所做的理论预测，包括与新物理学相关的可能偏差。一个特别令人感兴趣的效应是暗物质（DM）环境对黑洞及其随后合并的影响。虽然DM构成了宇宙能量预算的重要部分，但到目前为止，唯一确认的与其他物质的相互作用通道是通过引力相互作用。因此，研究DM在强重力环境中的行为可能是理解粒子物理学的唯一途径，例如，区分高质量和低质量粒子，并限制自相互作用。由DM环境引起的GW的偏差预计对于BH螺旋上升和振铃下降是小的，但是合并阶段没有很好地量化，并且在特定情况下可能会增强那里的影响。考虑到DM问题的重要性，以及探测器灵敏度的不断提高，这种效应值得进一步研究。方法：该项目将使用分析方法和最近开发的数值代码来研究孤立BH和BBHs的低质量玻色子暗物质环境。该项目还将涉及开发一个完全广义相对论的N体代码（作为GRChombo框架的一部分），以研究强弯曲时空中重暗物质候选者的行为，允许直接比较两种质量情况，这将使我们能够辨别每种情况的潜在可检测签名。很少有这样的混合NR/N体代码存在（据我们所知，只有一个），目前没有公开。STFC目标的相关性：拟议的项目福尔斯属于STFC的粒子天体物理学路线图主题基本物理与宇宙信息，特别是，它是相关的问题：（2a）什么是暗物质的性质？(2e)宇宙中是否存在尚未被直接或间接探测到的粒子？这些问题反过来又涉及科学技术促进委员会确定为其方案核心的科学挑战，即：（C）宇宙的基本组成部分和结构是什么，它们如何相互作用？(D)我们如何探索和理解宇宙的极端？这项工作也与丽莎合作的工作包8.7有关，这是欧空局/美国宇航局的空间引力波观测站使命。影响：高-有可能发现暗物质的特征，并区分高质量和低质量的候选者。开发公开可用的代码也为其他研究人员提供了宝贵的资源。合作者：学生将与GRChombo团队（www.grchombo.org）合作，作为开发开源数值相对论代码项目的一部分。这是一个由英国主导的社区资源，与英特尔合作开发，作为其高性能计算（HPC）技术的旗舰示例。他们还将作为准成员加入丽莎合作。

AIM: Develop numerical relativity simulations and analytic models of black holes (BHs) and black hole binaries (BHBs) in dark matter environments, comparing and contrasting the high and low mass candidates, and identifying observational signatures for each case. BACKGROUND: The 2015 detection of gravitational waves (GWs) by LIGO was a breakthrough moment for science. LIGO (and Virgo) are currently in their third observation run with over 30 new candidate events reported so far, and the next decade promises a deluge of new data detected by a world-wide network of GW instruments. It will also be a crucial stage in preparations for the LISA space based mission, which will expand our field of vision into frequencies which probe the rich DM environments of supermassive black holes (SMBHs) and background signals from the early universe (~ 10-4 - 10-1 Hz). To make sense of the data streams we will receive we need to fully understand the theoretical predictions that are made by current theories, such as General Relativity, including possible deviations relating to new physics. One effect which is of particular interest is the impact of dark matter (DM) environments on BHs and their subsequent merger. Whilst DM composes a significant fraction of the energy budget of the Universe, so far the only confirmed interaction channel with other matter is via gravitational interactions. Studies of the behaviour of DM in strong gravity environments may therefore be the only way to understand the particle physics, for example, to distinguish high mass and low mass particles, and constrain self interactions. The deviations in GWs resulting from DM environments are expected to be small for BH inspiral and ringdown, but the merger phase is not well quantified, and the effects there may be enhanced in specific situations. Given the importance of the DM question, and ever-increasing detector sensitivity, such effects merit further investigation. METHODS: The project will use analytic methods and recently developed numerical code to study low mass, bosonic dark matter environments for isolated BHs and BBHs. The project will also involve developing a fully general relativistic N-body code (as part of the GRChombo framework), to study the behaviour of heavy dark matter candidates in strongly curved spacetimes, permitting a direct comparison of the two mass cases which will allow us to discern potentially detectable signatures of each. Few such hybrid NR/N-body codes exist (to our knowledge, only one) and none are currently publicly available.RELEVANCE TO STFC GOALS: The proposed project falls within the STFC Roadmap for Particle Astrophysics theme Fundamental Physics with Cosmic Messengers, in particular, it is relevant to the questions: (2a) What is the nature of Dark Matter? (2e) Are there particles present in the universe which have not yet been detected either directly or indirectly?These in turn address the Science Challenges identified by STFC as core to its programme, namely: (C) What are the fundamental constituents and fabric of the universe and how do they interact? (D) How can we explore and understand the extremes of the universe? The work is also relevant to Work Packages 8.7 of the LISA collaboration, an ESA/NASA mission for a space based gravitational wave observatory. IMPACT: High - potential to discover signatures of dark matter and distinguish between high and low mass candidates. Development of publicly available code also provides an invaluable resource for other researchers. COLLABORATORS: The student will work with the GRChombo team (www.grchombo.org), as part of a project to develop an open source numerical relativity code. This is a UK-led community resource, developed in collaboration with Intel, as a flagship example of their High Performance Computing (HPC) technologies. They will also join the LISA collaboration as an associate member.