标题： 早期宇宙的低语：原初黑洞的回声 显示英文标题

标题： Whispers from the Early Universe: The Ringdown of Primordial Black Holes

摘要： 我们研究了原初黑洞（PBHs）在早期宇宙中形成时的回音阶段产生的随机引力波背景（SGWB）。由于回音信号与PBH形成机制无关，因此产生的SGWB提供了一种与模型无关的PBH探测方法。我们数值计算了回音波形并推导了相应的SGWB。我们表明，这种信号可能被未来的脉冲星计时阵列（PTAs）检测到，对于质量大于太阳质量的PBH而言。此外，我们评估了双PBH合并产生的SGWB，并证明其位于下一代地面干涉仪如Cosmic Explorer和Einstein Telescope的灵敏度带内，这表明了针对PBH暗物质情景的多频段观测策略。 显示英文摘要

摘要： We investigate the stochastic gravitational wave background (SGWB) generated by the ringdown phase of primordial black holes (PBHs) formed in the early universe. As the ringdown signal is independent of the PBH formation mechanism, the resulting SGWB offers a model-independent probe of PBHs. We numerically compute the ringdown waveform and derive the corresponding SGWB. We show that such a signal could be detected by future pulsar timing arrays (PTAs) for PBHs heavier than the solar mass. Additionally, we evaluate the SGWB from binary PBH mergers and demonstrate that it lies within the sensitivity bands of next-generation ground-based interferometers such as Cosmic Explorer and Einstein Telescope, suggesting a multi-band observational strategy for probing the PBH dark matter scenario.