AI 中文总结
本研究探讨LISA-TAIJIp与LISA-TAIJIm两种网络探测、区分各向同性SGWB偏振分量的能力，发现LISA-TAIJIm配置偏振简并性更弱，大角度网络更利于SGWB偏振测量。
AI 中文摘要
随机引力波背景（SGWB）为探测未解决的天体物理种群及早期宇宙的基础物理提供了独特机会。未来的空间引力波（GW）探测器，如LISA和TAIJI，将能够开展互相关观测，这类观测对SGWB及其偏振内容尤为敏感。本研究探讨了两种拟议的LISA-TAIJI网络——LISA-TAIJIp和LISA-TAIJIm，在探测和区分各向同性SGWB的张量、矢量和标量偏振分量方面的能力。利用两个网络之间的互相关，我们评估了它们对包含不同偏振组合的SGWB的灵敏度和信噪比。我们发现，两个星座间相对倾角更大的LISA-TAIJIm配置，表现出明显更弱的偏振简并性，且在分离偏振分量（尤其是张量-矢量-标量背景）方面的性能显著提升。对幂律SGWB的费舍尔矩阵预测显示，两种配置对谱参数的约束大致相当，这反映了分量分离与参数估计的不同作用。我们的结果表明，大角度LISA-TAIJI网络为模型无关的SGWB偏振测量提供了更有利的几何结构。
英文摘要
Stochastic gravitational-wave backgrounds (SGWBs) provide a unique opportunity to probe both unresolved astrophysical populations and fundamental physics in the early Universe. Future space-based gravitational-wave (GW) detectors, such as LISA and TAIJI, will enable cross-correlation observations that are particularly sensitive to SGWBs and their polarization content. In this work, we investigate the capabilities of two proposed LISA-TAIJI networks, LISA-TAIJIp and LISA-TAIJIm, for detecting and discriminating tensor, vector, and scalar polarization components of isotropic SGWBs. Using the cross-correlation between the two networks, we evaluate their sensitivities and signal-to-noise ratios for SGWBs containing different combinations of polarization sectors. We find that the LISA-TAIJIm configuration, which has a larger relative inclination between the two constellations, exhibits substantially weaker polarization degeneracies and significantly improved performance in separating polarization components, particularly for tensor-vector-scalar backgrounds. Fisher-matrix forecasts for power-law SGWBs show that the two configurations yield broadly comparable constraints on spectral parameters, reflecting the different roles of component separation and parameter estimation. Our results demonstrate that large-angle LISA-TAIJI networks provide a more favorable geometry for model-independent SGWB polarization measurements.
Comments22 pages, 14 figures
