Gravitational-wave signatures from compact binaries beyond general relativity and the standard model of particle physics

本论文的中心课题是在爱因斯坦广义相对论的框架下对致密双星系统进行数值模拟，并对该理论进行修正。这些模拟的目标是对这些双星产生的引力波信号的理论预测，特别关注粒子物理学和/或广义相对论标准模型之外的源的可能特征。这些特征将用于现有地面引力波探测器网络（LIGO，Virgo，KAGRA）以及未来的地面或空间天文台（如丽莎或爱因斯坦望远镜）的持续数据分析。一种特殊类型的物理系统是所谓的玻色子星，这是一种假设的由玻色子物质组成的紧凑恒星物体（例如标量场或矢量场）。他们的建模将采用独立的代码来建模单个玻色子星时空，以及使用GRChombo和Lean代码在3+1时空维度进行完整的数值模拟。我们的目标是特定的物理配置。首先，标量-张量引力理论中玻色子-恒星双星的螺旋和合并，其中一种称为自发世俗化的效应可能会导致显著的引力波发射，这与广义相对论中预期的信号截然不同。第二类双星是薄壁玻色子星，它们的合并可能会导致引力波发射的特征，不同于更常见的质量分布更均匀的致密物体合并。

The central topic of this thesis project is the numerical simulation of compact binary systems in the framework of Einstein's theory of general relativity and modification of this theory. These simulations target the theoretical prediction of gravitational-wave signals generated by these binaries with particular focus on possible signatures of sources beyond the standard model of particle physics and/or general relativity. These signatures are to be used in ongoing data analysis with the existing network of ground-based gravitational-wave detectors (LIGO, Virgo, KAGRA) as well as future ground or space based observatories such as LISA or the Einstein Telescope. A particular type of physical systems targeted are so-called boson stars, a hypothesised class of compact stellar objects composed of bosonic matter (e.g. scalar or vector fields). Their modelling will employ stand-alone codes for the modelling of single boson-star spacetimes as well as full numerical simulations in 3+1 space-time dimensions using the GRChombo and Lean codes. We target to specific physical configurations. First, the inspiral and merger of boson-star binaries in scalar-tensor theory of gravity where an effect called spontaneous secularisation will likely result in prominent gravitational-wave emission that differs strongly from the signals expected in general relativity. The second class of binaries are thin-wall boson stars whose merger will likely result in characteristic features in the gravitational-wave emission different from the more common mergers of compact objects with more homogeneous mass distributions.