AI 中文总结
研究双白矮星作为LISA引力波源及背景，通过COMPAS框架生成合成群体，构建引力波背景并研究其对双星分析假设的依赖性，发现背景对关键双星演化参数敏感，LISA观测有潜力约束双星演化模型。
AI 中文摘要
引力波已被证明是致密双星群体的有力探测手段。在激光干涉空间天线LISA可探测的毫赫兹频率范围内，双白矮星预计是主要的引力波源，会形成可单独分辨的信号和未分辨的银河背景。本文构建了类似银河系的群体模型，计算了LISA灵敏度范围内未分辨的银河系双白矮星产生的引力波背景，特别强调探索和限制双星演化中的不确定性。采用COMPAS双星群体合成框架生成银河系中双白矮星的合成群体，使用各种物理动机的演化处方和初始模型参数研究不同的双白矮星群体。从这些群体构建引力波背景，研究背景谱对双星分析假设的依赖性，讨论LISA引力波观测对双星演化的约束可能性。发现背景的形状和幅度对共同包层演化和质量转移效率等关键双星演化参数敏感，这些假设的变化导致预测背景谱有可测量的差异。结果表明LISA对未分辨的双白矮星背景的观测有潜力约束双星演化模型，凸显了引力波背景建模作为研究银河系中致密双星形成和演化的补充工具的重要性。
英文摘要
Gravitational waves (GWs) have proven to be a powerful probe of compact binary populations. In the millihertz frequency range accessible to Laser Interferometer Space Antenna LISA, binary white dwarfs (BWDs) are expected to constitute a dominant source, forming both individually resolvable signals and an unresolved Galactic background. In this work, we construct a Milky Way like population model and calculate the GW background from unresolved Galactic BWD in the LISA sensitivity range, with particular emphasis on exploring and constraining uncertainties in binary stellar evolution. We employ COMPAS binary population synthesis framework to generate synthetic populations of BWD in the Milky Way. Various physically motivated evolution prescriptions and initial model parameters are used to study diverse population of BWDs. From these populations, we construct the GW background and investigate the dependence of the background spectrum on the assumptions on binary analysis. We discuss the possibility of constraints on binary evolution that LISA GW observations may yield. We find that the shape and amplitude of the background are sensitive to key binary evolution parameters like common envelope evolution and mass-transfer efficiencies. Variations in these assumptions lead to measurable differences in the predicted background spectrum. Our results demonstrate that LISA observations of the unresolved BWD background have the potential to constrain binary evolution models. This highlights the importance of GW background modelling as a complementary tool for studying the formation and evolution of compact binaries in the Milky Way.
Comments13 pages with 5 figures and 2 tables; comments welcome
