标题： 多面超冷：从PTA到LIGO 显示英文标题

标题： Multifaceted Supercooling: From PTA to LIGO

摘要： 超冷相变，如在近共形和禁闭标准模型（SM）扩展中所预测的，是强随机引力波背景（SGWBs）的确定性来源。 在本工作中，我们研究了这种相变的另一个方面：它们对来自独立宇宙学源的引力波频谱的显著且 largely 未被探索的影响。 聚焦于由亚稳态宇宙弦网络产生的引力波，我们表明，一个介入的超冷相，引发热膨胀，可以重塑并抑制频谱的高频部分。 这一机制重新开放了之前因LIGO的零结果而被排除的弦参数空间区域，同时与脉冲星计时阵列（PTAs）报告的纳赫兹SGWB信号相容。 所产生的总频谱通常表现出双组分结构，由弦衰变和相变本身共同产生，使该情景具有观测上的独特性。 我们系统地分类了可行的参数空间，并确定了未来探测器如Advanced LIGO、LISA和ET可探测的区域。 显示英文摘要

摘要： Supercooled phase transitions, as predicted, e.g., in near-conformal and confining extensions of the Standard Model (SM), are established sources of strong stochastic gravitational wave backgrounds (SGWBs). In this work, we investigate another facet of such transitions: their significant and largely uncharted impact on gravitational wave spectra originating from independent cosmological sources. Focusing on gravitational waves produced by a metastable cosmic string network, we show that an intervening supercooled phase, initiating thermal inflation, can reshape and suppress the high-frequency part of the spectrum. This mechanism reopens regions of string parameter space previously excluded by LIGO's null results, while remaining compatible with the nanohertz SGWB signal reported by pulsar timing arrays (PTAs). The resulting total spectrum typically exhibits a dual-component structure, sourced by both string decay and the phase transition itself, rendering the scenario observationally distinctive. We systematically classify the viable parameter space and identify regions accessible to upcoming detectors such as Advanced LIGO, LISA, and ET.