模拟LISA数据挑战中的随机引力波背景辨识

Signal identification of the stochastic gravitational wave background in the Mock LISA Data Challenge

探测随机引力波背景,揭示极早期宇宙的演化过程和天体物理源族群特性是空间引力波探测计划的主要科学目标之一,将对基础物理和天体物理学产生重大影响.本文系统阐述了单个空间引力波探测器探测随机引力波背景的零通道方法,并对仪器噪声进行了详细的建模与分析.在此基础上,我们对模拟LISA数据挑战中的项目3.5展开实战.在贝叶斯数据分析框架下,本文采用马尔科夫链蒙特卡罗算法对模拟数据集中的物理参数进行评估,成功反演出仪器噪声和随机引力波背景,实现了对复杂噪声中随机引力波背景的精确辨识.

Detecting the stochastic gravitational wave background,revealing the evolutionary processes of the very early universe along with the characteristics of astrophysical source populations is among the leading scientific objectives of the spaceborne gravitational wave detector,which will significantly advance our understanding in fundamental physics and astrophysics.In this work,we introduce the null channel method for detecting the stochastic gravitational wave background within a single LISA-like space gravitational wave detector,as well as model and analyze the instrument noise in detail.Based on this,we put the Mock LISA Data Challenge 3.5 training dataset into practice.In the Bayesian data analysis framework,Markov chain Monte Carlo algorithm is used to directly evaluate the physical parameters of the injected signal,and the instrument noise and stochastic gravitational wave background are accurately reconstructed.