{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2018:UNFMXUPHCZFJWRLCXRFNYDFXKE","short_pith_number":"pith:UNFMXUPH","schema_version":"1.0","canonical_sha256":"a34acbd1e7164a9b4562bc4adc0cb751365e653563563938fd17059b218fa3e8","source":{"kind":"arxiv","id":"1812.05157","version":2},"attestation_state":"computed","paper":{"title":"Lepton Number and Expansion of the Universe","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"hep-ph","authors_text":"Cheng Tao Yang, Jeremiah Birrell, Johann Rafelski","submitted_at":"2018-12-12T21:18:07Z","abstract_excerpt":"We show that the non-integer effective number of neutrinos $N^{\\mathrm{eff}}_\\nu$ can be understood as an effect of lepton $L$ asymmetry in the early Universe carried by the Dirac neutrino cosmic background. We show that $N_\\nu^{\\mathrm{eff}}=3.36\\pm0.34$ (CMB only) and $N_\\nu^{\\mathrm{eff}}= 3.62\\pm0.25$ (CMB and $H_0$) require a ratio between baryon number $B$ and lepton number to be $1.16 \\times 10^{-9}\\leqslant B/|L|\\leqslant 1.51 \\times 10^{-9}$. These values are close to the baryon-to-photon ratio $0.57\\times 10^{-9}\\leqslant B/N_\\gamma \\leqslant 0.67\\times10^{-9}$. Thus instead of the u"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1812.05157","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"hep-ph","submitted_at":"2018-12-12T21:18:07Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"a2a9b5ff3127990287d359e6a83a29dd337e220bf6e23662878f8f1659c82707","abstract_canon_sha256":"4c1427cfb01ec3bc1dca45b3ae07feeb2b187a93163351ef83130127841f83b3"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:56:12.455198Z","signature_b64":"PUcvU/2FhwxK9C23q5MXupEg0ymS3XFtlyylwxB69jFZuSNfk/YPWZgMPeiGBrfsm+ZCGg24tYDnVoH+dhigDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a34acbd1e7164a9b4562bc4adc0cb751365e653563563938fd17059b218fa3e8","last_reissued_at":"2026-05-17T23:56:12.454569Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:56:12.454569Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Lepton Number and Expansion of the Universe","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"hep-ph","authors_text":"Cheng Tao Yang, Jeremiah Birrell, Johann Rafelski","submitted_at":"2018-12-12T21:18:07Z","abstract_excerpt":"We show that the non-integer effective number of neutrinos $N^{\\mathrm{eff}}_\\nu$ can be understood as an effect of lepton $L$ asymmetry in the early Universe carried by the Dirac neutrino cosmic background. We show that $N_\\nu^{\\mathrm{eff}}=3.36\\pm0.34$ (CMB only) and $N_\\nu^{\\mathrm{eff}}= 3.62\\pm0.25$ (CMB and $H_0$) require a ratio between baryon number $B$ and lepton number to be $1.16 \\times 10^{-9}\\leqslant B/|L|\\leqslant 1.51 \\times 10^{-9}$. These values are close to the baryon-to-photon ratio $0.57\\times 10^{-9}\\leqslant B/N_\\gamma \\leqslant 0.67\\times10^{-9}$. Thus instead of the u"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.05157","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1812.05157","created_at":"2026-05-17T23:56:12.454681+00:00"},{"alias_kind":"arxiv_version","alias_value":"1812.05157v2","created_at":"2026-05-17T23:56:12.454681+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.05157","created_at":"2026-05-17T23:56:12.454681+00:00"},{"alias_kind":"pith_short_12","alias_value":"UNFMXUPHCZFJ","created_at":"2026-05-18T12:32:56.356000+00:00"},{"alias_kind":"pith_short_16","alias_value":"UNFMXUPHCZFJWRLC","created_at":"2026-05-18T12:32:56.356000+00:00"},{"alias_kind":"pith_short_8","alias_value":"UNFMXUPH","created_at":"2026-05-18T12:32:56.356000+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE","json":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE.json","graph_json":"https://pith.science/api/pith-number/UNFMXUPHCZFJWRLCXRFNYDFXKE/graph.json","events_json":"https://pith.science/api/pith-number/UNFMXUPHCZFJWRLCXRFNYDFXKE/events.json","paper":"https://pith.science/paper/UNFMXUPH"},"agent_actions":{"view_html":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE","download_json":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE.json","view_paper":"https://pith.science/paper/UNFMXUPH","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1812.05157&json=true","fetch_graph":"https://pith.science/api/pith-number/UNFMXUPHCZFJWRLCXRFNYDFXKE/graph.json","fetch_events":"https://pith.science/api/pith-number/UNFMXUPHCZFJWRLCXRFNYDFXKE/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE/action/timestamp_anchor","attest_storage":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE/action/storage_attestation","attest_author":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE/action/author_attestation","sign_citation":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE/action/citation_signature","submit_replication":"https://pith.science/pith/UNFMXUPHCZFJWRLCXRFNYDFXKE/action/replication_record"}},"created_at":"2026-05-17T23:56:12.454681+00:00","updated_at":"2026-05-17T23:56:12.454681+00:00"}