AI 中文总结
研究针对天基引力波观测中时钟抖动影响参数推断的问题，在几何TDI框架中制定时钟噪声减法方案，通过引入广义可观测量实现减法，经模拟测试，该方法能抑制噪声、恢复灵敏度并改善参数约束，证明其对精密数据分析的必要性。
AI 中文摘要
利用天基干涉仪进行毫赫兹引力波观测需要时延干涉（TDI）可观测量，其残余仪器噪声需得到充分控制以用于探测和参数推断。尽管TDI抑制了不等时和时变臂中的激光相位噪声，但机载超稳振荡器的时钟抖动可能仍高于二次噪声本底并影响数据分析中的有效噪声加权。我们在几何TDI框架中直接制定了一种时钟噪声减法方案。该构建为允许延迟和时间提前算子时出现的四种时空链路结构引入了广义时钟噪声可观测量。这使得时钟噪声残余在代数上与激光噪声残余平行，并为任意双路径几何TDI可观测量产生明确的减法项。我们用代表性第一代和第二代几何TDI组合说明了该方法，并用类似LISA轨道和噪声水平的时域模拟对其进行了测试。对于改进的第二代U型可观测量，减法将时钟噪声残余抑制到信号区域以下，恢复了对单色源的预期灵敏度，并改善了对源幅度、频率和相位的费舍尔和马尔可夫链蒙特卡罗参数约束。这些结果表明，时钟噪声校准是未来天基引力波探测器精密数据分析的必要组成部分。
英文摘要
Millihertz gravitational-wave observations with space-based interferometers require time-delay interferometry (TDI) observables whose residual instrumental noise is sufficiently controlled for both detection and parameter inference. Although TDI suppresses laser phase noise in unequal and time-dependent arms, clock jitter from onboard ultra-stable oscillators can remain above the secondary-noise floor and bias the effective noise weighting used in data analysis. We formulate a clock-noise subtraction scheme directly in the geometric-TDI framework. The construction introduces generalized clock-noise observables for the four space-time link structures that arise when both delay and time-advance operators are allowed. This makes the clock-noise residual algebraically parallel to the laser-noise residual and yields explicit subtraction terms for arbitrary two-path geometric TDI observables. We illustrate the method with representative first- and second-generation geometric TDI combinations, and test it with time-domain simulations using LISA-like orbits and noise levels. For a modified second-generation U-type observable, the subtraction suppresses the clock-noise residual below the signal region, restores the expected sensitivity to a monochromatic source, and improves the Fisher and Markov-chain Monte Carlo parameter constraints on the source amplitude, frequency and phase. These results show that clock-noise calibration is a necessary component of precision data analysis for future space-based gravitational-wave detectors.
