Gravitational wave astronomy

引力波天文学的出现正在迅速改变天体物理学的格局。从2015年对合并黑洞的突破性探测到2017年8月令人震惊的中子星双子星事件，再到LIGO-Virgo科学合作项目在当前观测运行期间发出的定期警报，很明显，引力波宇宙比人们预期的要丰富得多。这个天文学新领域的影响和发现潜力是相当可观的。随着引力波仪器灵敏度的提高，更大范围的引力波源应该触手可及。与电磁对应的进一步独特事件（如GW170817）将有助于解决长期存在的谜团，从紧凑双星系统的形成和演化到短伽马射线爆发的中心引擎，从中子星核心极端压力下的物质细节到黑洞动力学，以及（通过千新星特征）宇宙中重元素的形成。为了实现当前和未来仪器的科学潜力，我们需要完善我们对相关理论的理解。地面和太空探测器都是如此。当我们准备第三代地面干涉仪（如爱因斯坦望远镜或宇宙探索者）时，我们需要更精确的中子星天体物理学模型，包括可靠的非线性合并事件模拟。同样，为了准备在21世纪30年代初LISA发射后对低频引力波天空进行天基观测，我们必须改进超大质量黑洞的动力学模型。这些都不是遥远的计划；需要立即在理论上取得进展，以便为仪器和数据分析策略的设计提供信息。这项研究计划建立在南安普顿重力小组在黑洞、中子星和引力波天体物理学方面的专业知识基础上，旨在深入了解黑洞和中子星的动力学、相关的观测特征，以及如何利用这些信号提供有关物理的信息。该计划具有高度相互关联的性质，有五个不同的主题，需要类似的方法（例如广义相对论摄动理论或数值模拟）和物理输入（例如超流体，磁场或引力辐射反应）。总体目标是开发出显著改进的模型，这些模型可以在未来一系列渠道的高精度观测中进行测试。自然重点是涉及中子星和黑洞的问题。这些迷人而神秘的物体涉及鼓舞人心的科学，代表着探索极端物理的独特实验室。黑洞天体物理学对一系列基本问题产生影响，从引力的性质到宇宙学中的问题，例如与早期宇宙结构形成有关的问题。与此同时，中子星观测使我们能够在极端条件下探测物质的状态，为我们提供了从欧洲核子研究中心（CERN）的大型强子对撞机（Large Hadron Collider）等对撞机收集到的信息。这些高度相对性系统的建模涉及到在实验室无法获得的广泛的物理学。随着我们观测能力的提高，我们正在达到这样一个地步，即首先需要精确的建模来解释数据并促进观测。拟议的研究计划代表了一项连贯的努力，以探索黑洞和中子星的天体物理学，以提高我们对宇宙基本物理定律的理解，并揭示自然如何在我们目前理解不足的尺度上运作，这一主题仍然是STFC任务的核心。

The emergence of gravitational-wave astronomy is rapidly changing the astrophysics landscape. From the breakthrough detection of merging black holes in 2015 to the astonishing neutron-star binary event from August 2017 and the regular alerts sent out by the LIGO-Virgo Scientific collaboration during the current observing run, it is clear that the gravitational-wave universe is richer than one might have expected. The impact and discovery potential of this new area of astronomy is considerable. As the sensitivity of the gravitational-wave instruments improves, a broader range of sources should come within reach. Further unique events (like GW170817) associated with electromagnetic counterparts will help resolve long-standing mysteries ranging from the formation and evolution of compact binarysystems to the central engine of short gamma-ray bursts, from the details of matter under the extreme pressures of a neutron star core to the dynamics of black holes and (through kilonova signatures) the formation of heavy elements in the Universe. In order to realise the science potential of current and future instruments, we need to refine our understanding of the relevant theory. This is true for both ground- and space-based detectors. As we prepare for the third generation of ground-based interferometers (like the Einstein Telescope or the Cosmic Explorer) we need more precise models for neutron star astrophysics, including reliable nonlinear simulations of merger events. Similarly, preparing for space-based observations of the low-frequency gravitational-wave sky following the LISA launch in the early 2030s, we have to improve our dynamical models of supermassive black holes. These are not distant plans; immediate progress on the theory is required to inform the design of both instruments and data analysis strategies.This research proposal builds on the Southampton Gravity Group's expertise in black hole, neutron star and gravitational-wave astrophysics, and is aimed at developing a deeper understanding of the dynamics of black holes and neutron stars, the associated observational signatures and how these signals can be used to provide information about the involved physics. The programme is of a highly interconnected nature with five different themes requiring similar methodology (e.g. general relativistic perturbation theory or numerical simulations) and physics input (e.g. superfluidity, magnetic fields or gravitational radiation reaction). The overall aim is to develop significantly improved models that can be tested against future high-precision observations in a range of channels. The natural emphasis is on problems involving neutron stars and black holes. Thesefascinating and enigmatic objects involve inspirational science and represent unique laboratories for the exploration of the extremes of physics. Black-hole astrophysics impacts on a range of fundamental issues, from the nature of gravity to problems in cosmology, e.g., associated with structure formation in the early Universe. Meanwhile, neutron star observations allow us to probe the state of matter under extreme conditions, providing us with information which complements that gleaned from colliders like the Large Hadron Collider at CERN. The modelling of these highly relativistic systems involves a broad range of physics that is not accessible in the laboratory. As our observational capabilities improve, we are reaching the point where precise modelling is required both to interpret data and to facilitate the observations in the first place.The proposed research programme represents a coherent effort to explore the astrophysics of black holes and neutron stars in order to improve our understanding of the fundamental laws of physics of the Universe and reveal how nature operates on scales where our current understanding breaks down, a theme that remains central to the STFC mission.