{"paper":{"title":"Constraints on Primordial Black Holes","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Updated limits restrict primordial black holes to a small fraction of the universe's mass across 10^{-5} to 10^{50} g.","cross_cats":["gr-qc","hep-ph","hep-th"],"primary_cat":"astro-ph.CO","authors_text":"Bernard Carr, Jun'ichi Yokoyama, Kazunori Kohri, Yuuiti Sendouda","submitted_at":"2020-02-27T05:17:54Z","abstract_excerpt":"We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range $10^{-5}\\text{--}10^{50}$ g. Those smaller than $\\sim 10^{15}$ g would have evaporated by now due to Hawking radiation, so their abundance at formation is constrained by the effects of evaporated particles on big bang nucleosynthesis, the cosmic microwave background (CMB), the Galactic and extragalactic $\\gamma$-ray and cosmic ray backgrounds and the possible generation of stable Planck mass relics. PBHs larger than $\\sim 10^{15}$ g are subject to a variety of con"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range 10^{-5}--10^{50} g.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"Many of the constraints are associated with observational or theoretical uncertainties.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Updated compilation shows PBHs are tightly constrained across 55 orders of magnitude in mass, ruling out dominant dark matter contributions except in narrow windows, with many limits carrying observational uncertainties.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Updated limits restrict primordial black holes to a small fraction of the universe's mass across 10^{-5} to 10^{50} g.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"4b8c765b9a51e7b179fa1589d002e6ee175b9f38e7ba6cba10d8414aabe8e701"},"source":{"id":"2002.12778","kind":"arxiv","version":2},"verdict":{"id":"351d6065-c081-40f7-bfaf-593ed4f4efd5","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T02:48:55.155179Z","strongest_claim":"We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range 10^{-5}--10^{50} g.","one_line_summary":"Updated compilation shows PBHs are tightly constrained across 55 orders of magnitude in mass, ruling out dominant dark matter contributions except in narrow windows, with many limits carrying observational uncertainties.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"Many of the constraints are associated with observational or theoretical uncertainties.","pith_extraction_headline":"Updated limits restrict primordial black holes to a small fraction of the universe's mass across 10^{-5} to 10^{50} g."},"references":{"count":300,"sample":[{"doi":"","year":null,"title":"This applies generically if the PBHs form from density fluctuations with a δ-function power spectrum","work_id":"f47b0cd3-a9f2-40d6-8234-f3287ba66b85","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"stupendously large black holes","work_id":"0d178a22-7c1b-42c4-b532-68e4c3ecdd86","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1967,"title":"Y. B. Zel’dovich and I. D. Novikov, Sov. Astron. 10, 602 (1967)","work_id":"2d394ead-b84f-4345-a4f6-d5b3f1eef0ef","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1974,"title":"S. W. Hawking, Nature 248, 30 (1974)","work_id":"73b2c09f-e2a1-475d-be72-c3b324acd8e8","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2016,"title":"Planck 2015 results. XIII. Cosmological parameters","work_id":"a36b7348-19d6-4af7-9627-ad462b9f2c8a","ref_index":5,"cited_arxiv_id":"1502.01589","is_internal_anchor":true}],"resolved_work":300,"snapshot_sha256":"db9935ed60ef7f414ec09dd592bd90d564a62491e90ed9d3c1da0839bd8bd5af","internal_anchors":171},"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"}