发表机构
Monash University（莫纳什大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究针对宇宙学相变，提出基于泡寿命分布一阶矩的新时间尺度β_ν，可更准确描述成核泡集合，其能使预测的引力波频谱峰值振幅偏移达一个数量级，为相关理论预测提供改进方向。
AI 中文摘要
早期宇宙中的一阶相变可产生随机引力波背景，为高能物理提供独特探测手段。本研究聚焦于对塑造引力波频谱起核心作用的泡成核与相变时间尺度相关问题。诸多常用方法通过假真空衰变率的泰勒展开表征相变率，我们提出更基础的描述应基于泡寿命的分布，并定义新时间尺度β_ν为该分布的一阶矩。研究表明，β_ν在合适极限下可复现以往时间尺度定义的行为，同时避免其存在的问题，为成核泡集合提供更自然的描述。我们进一步量化该改进时间尺度对预测引力波频谱的影响，发现其相较于以往定义可使峰值振幅偏移达一个数量级。随着下一代引力波探测器投入使用，可靠的理论预测至关重要，本研究有望朝该方向迈出一步。
英文摘要
First-order phase transitions in the early universe can generate a stochastic background of gravitational waves, offering a unique probe of high-energy physics. In this work, we investigate aspects of bubble nucleation and transition timescales, which play a central role in shaping the resulting gravitational wave spectrum. Many common approaches characterise the transition rate via a Taylor expansion of the false vacuum decay rate. We argue that a more fundamental description is instead given by the distribution of bubble lifetimes, and define a new timescale, $β_ν$, as the first moment of this distribution. We show that $β_ν$ reproduces the behaviour of previous timescale definitions in the appropriate limits, while avoiding their pathologies, and offers a more natural description of the ensemble of nucleated bubbles. We then quantify the impact of this improved timescale on the predicted gravitational wave spectrum, finding that it shifts the peak amplitude by up to an order of magnitude relative to previous definitions. As next-generation gravitational wave detectors come online, robust theoretical predictions will be essential; we hope this work represents a step in that direction.
Comments28 pages, 6 figures
