Within its observational band the Laser Interferometer Space Antenna, LISA, will simultaneously observe orbital modulated waveforms from Galactic white dwarf binaries, a binary black hole produced gravitational-wave background, and potentially a cosmologically created stochastic gravitational-wave background (SGWB). The overwhelming majority of stars end their lives as white dwarfs, making them very numerous in the Milky Way. We simulate Galactic white dwarf binary gravitational-wave emission based on distributions from various mock catalogues and determine a complex waveform from the Galactic foreground with 3.5 × 107 binaries. We describe the effects from the Galactic binary distribution population across mass, position within the Galaxy, core type, and orbital frequency distribution. We generate the modulated Galactic white dwarf signal detected by LISA due to its orbital motion, and present a data analysis strategy to address it. The Fisher Information and Markov Chain Monte Carlo methods give an estimation of the LISA noise and the parameters for the different signal classes. We estimate the detectable limits for the future LISA observation of the SGWB in the spectral domain with the three LISA channels A, E, and T. We simultaneously estimate the Galactic foreground, the astrophysical and cosmological backgrounds. Assuming the expected astrophysical background and a Galactic foreground, a cosmological background energy density of around ΩGW,cosmo ≈ 8 × 10−13 could be detected by LISA. LISA will either detect a cosmologically produced SGWB, or set a limit that will have important consequences.

中文翻译：

---

调制银河前景背景下 LISA 随机引力波背景的光谱分离

在其观测波段内，激光干涉仪空间天线 LISA 将同时观测银河白矮星双星的轨道调制波形、双星黑洞产生的引力波背景，以及可能是宇宙学产生的随机引力波背景 (SGWB)。绝大多数恒星以白矮星的形式结束生命，这使得它们在银河系中非常多。我们根据来自各种模拟目录的分布来模拟银河白矮星双星引力波发射，并确定来自银河前景的 3.5 × 107 双星的复杂波形。我们描述了银河二元分布种群对质量、银河内位置、核心类型和轨道频率分布的影响。我们生成了 LISA 由于其轨道运动而检测到的调制银河白矮星信号，并提出了一种数据分析策略来解决它。Fisher Information 和 Markov Chain Monte Carlo 方法对 LISA 噪声和不同信号类别的参数进行了估计。我们用三个 LISA 通道 A、E 和 T 估计了未来在光谱域中对 SGWB 的 LISA 观测的可检测极限。我们同时估计了银河前景、天体物理学和宇宙学背景。假设预期的天体物理背景和银河前景，LISA 可以检测到大约 ΩGW,cosmo ≈ 8 × 10−13 的宇宙学背景能量密度。LISA 要么检测宇宙学产生的 SGWB，要么设置一个会产生重要后果的限制。