辐射主导时期原初黑洞形成的长期3+1维模拟
Long-term 3+1 simulations of primordial black hole formation during radiation domination
- University of Chinese Academy of Sciences (UCAS)（中国科学院大学）
- Hangzhou Institute for Advanced Study (HIAS)（杭州高等研究院）
- Institute of Theoretical Physics, Chinese Academy of Sciences (CAS)（中国科学院理论物理研究所）
- Ningbo University（宁波大学）
- Asia Pacific Center for Theoretical Physics (APCTP)（亚太理论物理中心）
- Nagoya University（名古屋大学）
- Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI)（小林-益川粒子宇宙起源研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究开发了一套三维数值相对论框架，通过引入标度化伽马驱动项提升计算效率，模拟辐射主导宇宙中PBH形成，验证了其可追踪近临界坍缩与后期演化，为后续研究提供基础。
AI中文摘要：
我们开发了一套高效的三维数值相对论框架，用于研究辐射主导宇宙中来自超视界曲率扰动的原初黑洞（PBH）形成过程。我们在自适应网格细化程序\textsc{GRChombo}中实现了通量守恒相对论流体动力学，并引入了宇宙学标度化的伽马驱动项，该驱动项可使宇宙时间步长与标度因子成比例增长。在一次具有代表性的长期模拟中，该标度化驱动项在保持表观视界质量演化和约束行为的同时，与标准驱动项相比，将粗层级推进的次数减少了约94倍。我们还构造了共形时间版本的移动穿刺规范作为独立验证。将该框架应用于球对称高斯曲率轮廓，我们得到坍缩阈值为0.79578 < μ_c < 0.79580，临界指数γ ≈ 0.3559，与之前球对称结果一致。我们进一步将后期PBH质量增长拟合到Zel'dovich-Novikov吸积定律，证明该程序能够在三维中同时追踪近临界坍缩和形成后的长期演化。该框架为后续研究超越球对称性的PBH形成提供了基础。
英文摘要：
We develop an efficient three-dimensional numerical-relativity framework for primordial black-hole (PBH) formation from superhorizon curvature perturbations in a radiation-dominated Universe. We implement flux-conservative relativistic hydrodynamics in the adaptive-mesh-refinement code \textsc{GRChombo} and introduce a cosmologically scaled Gamma-driver that allows the cosmic-time step to grow in proportion to the scale factor. For a representative long-term simulation, the scaled driver preserves the apparent-horizon mass evolution and constraint behavior while reducing the number of coarse-level advances by a factor of approximately $94$ relative to the standard driver. We also construct a conformal-time version of the moving-puncture gauge as an independent check. Applying the framework to a spherical Gaussian curvature profile, we find a collapse threshold $0.79578 < μ_c < 0.79580$ and a critical exponent $γ\simeq 0.3559$, consistent with previous spherically symmetric results. We further fit the late-time PBH mass growth to the Zel'dovich--Novikov accretion law, demonstrating that the code can follow both near-critical collapse and long-term post-formation evolution in three dimensions. The framework provides a foundation for future studies of PBH formation beyond spherical symmetry.
