Zhuan Ning, Rong-Gen Cai, Shao-Jiang Wang, Chul-Moon Yoo
Abstract
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 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 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
arXiv did not return neighbours for this paper. Try again in a bit.