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框架下对紧致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进行理论预测，特别关注超越粒子物理和/或广义相对论标准模型的源的可能特征。这些签名将用于与现有的地面引力波探测器网络(LIGO、Virgo、KAGRA)以及未来的地面或空间观测站(如LISA或爱因斯坦望远镜)进行的数据分析。目标物理系统的一种特殊类型是所谓的玻色子恒星，这是一种假设的由玻色子物质(例如标量场或矢量场)组成的致密恒星对象的类别。他们的建模将采用单色色子-恒星时空建模的独立代码，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，引力标量张量理论中玻色子-恒星双星的激发和合并，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有很大不同。第二类双星是薄壁玻色子恒星，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具有更均匀质量分布的致密天体的合并。

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.