{"paper":{"title":"Long-term 3+1 simulations of primordial black hole formation during radiation domination","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","hep-ph"],"primary_cat":"gr-qc","authors_text":"Chul-Moon Yoo, Rong-Gen Cai, Shao-Jiang Wang, Zhuan Ning","submitted_at":"2026-08-13T13:08:52Z","abstract_excerpt":"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-l"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2608.13206","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2608.13206/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}