发表机构
Deutsches Elektronen-Synchrotron DESY; SISSA International School for Advanced Studies; INFN, Sezione di Trieste（德国电子同步加速器; 国际高等研究院; 意大利国家核物理研究所的里雅斯特分部）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对高度相对论真空气泡碰撞引力波模拟成本过高问题，开发了成对代理模型，可高效获取双气泡及多气泡系统的引力波频谱，为相关研究提供了低成本途径。
AI 中文摘要
来自真空一阶相变的引力波可探测相对论气泡碰撞的非线性动力学，预测其频谱需解析包含大量气泡的体积中洛伦兹收缩的标量气泡壁，这使得大加速机制下的直接格点模拟成本过高。我们开发了一种基于模拟的成对代理模型，将微观碰撞动力学与多气泡相变的几何结构分离，利用经对称性约化的(1+1)维标量场模拟构建双气泡引力波频谱库，包含碰撞后的非线性演化，这些频谱与考虑其他气泡屏蔽效应的几何权重结合。我们将双气泡频谱及三气泡、多气泡系统的重构频谱与完整(3+1)维格点模拟进行对比测试，该代理模型不仅计算成本可降低数个数量级，还能实现直接多气泡模拟实际无法触及的高度相对论碰撞研究，为探究频谱振幅和形状如何依赖碰撞加速及标量势提供了途径。
英文摘要
Gravitational waves from vacuum first-order phase transitions probe the nonlinear dynamics of relativistic bubble collisions. Predicting their spectrum requires resolving Lorentz-contracted scalar bubble walls throughout a volume containing many bubbles, making the large-boost regime prohibitively expensive for direct lattice simulations. We develop a simulation-based pairwise surrogate that separates the microscopic collision dynamics from the geometry of the multi-bubble transition. This utilizes symmetry-reduced $(1+1)$-dimensional scalar-field simulations to build a library of two-bubble gravitational-wave spectra, including the nonlinear post-collision evolution. These spectra are combined with geometric weights that account for screening by other bubbles. We test the two-bubble spectra and the reconstructed spectra of three- and many-bubble systems against full $(3+1)$-dimensional lattice simulations. Not only can the surrogate be orders of magnitude cheaper computationally, but it also provides access to highly relativistic collisions beyond the practical reach of direct many-bubble simulations. This provides a route to studying how the spectral amplitude and shape depend on the collision boost and scalar potential.
Comments18+6 pages, 8+6 figures
