标题： 超越地平线的高潮：来自由膨胀宇宙弦束缚的膜世界的更多引力波 显示英文标题

标题： Crescendo Beyond the Horizon: More Gravitational Waves from Domain Walls Bounded by Inflated Cosmic Strings

摘要： 引力波(GW)信号为研究早期宇宙的动力学提供了一个独特的窗口。 GW可能由早期宇宙中产生的拓扑缺陷产生，这些缺陷包含了关于紫外物理对称性的信息。 我们考虑一种情况，即两步相变产生了由宇宙弦包围的域墙网络。 具体来说，我们关注对称性破缺尺度存在层次的情况，并且在第二次相变之前，暴胀将第一次相变产生的宇宙弦推到了视界之外。 我们表明，这种弦-墙网络的演化和坍缩产生的GW信号具有独特的频谱，其信号强度可能相当大。 特别是，根据模型参数，所产生的信号可以在广泛的频率范围内出现，并可能被多种未来的探测器发现，包括脉冲星计时阵列以及空间和地面引力波观测站。 作为一个自然产生这种情况的例子，我们提出一个模型，其中第一次相变之后是一个由负责第二次对称性破缺的场驱动的短暂热暴胀时期。 该模型可以嵌入到一个超对称框架中，这为该场景提供了一个自然的实现。 在这种情况下，成功探测到GW频谱的峰值可以探测到软超对称性破缺尺度和墙张力。 显示英文摘要

摘要： Gravitational-wave (GW) signals offer a unique window into the dynamics of the early universe. GWs may be generated by the topological defects produced in the early universe, which contain information on the symmetry of UV physics. We consider the case in which a two-step phase transition produces a network of domain walls bounded by cosmic strings. Specifically, we focus on the case in which there is a hierarchy in the symmetry-breaking scales, and a period of inflation pushes the cosmic string generated in the first phase transition outside the horizon before the second phase transition. We show that the GW signal from the evolution and collapse of this string-wall network has a unique spectrum, and the resulting signal strength can be sizeable. In particular, depending on the model parameters, the resulting signal can show up in a broad range of frequencies and can be discovered by a multitude of future probes, including the pulsar timing arrays and space- and ground-based GW observatories. As an example that naturally gives rise to this scenario, we present a model with the first phase transition followed by a brief period of thermal inflation driven by the field responsible for the second stage of symmetry breaking. The model can be embedded into a supersymmetric setup, which provides a natural realization of this scenario. In this case, the successful detection of the peak of the GW spectrum probes the soft supersymmetry breaking scale and the wall tension.