{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:1999:SR3JRAVUPCEKMH3PYOVW43IPMH","short_pith_number":"pith:SR3JRAVU","schema_version":"1.0","canonical_sha256":"94769882b47888a61f6fc3ab6e6d0f61f08e8a0db844e476671d0a371f933262","source":{"kind":"arxiv","id":"astro-ph/9909275","version":2},"attestation_state":"computed","paper":{"title":"A New Calculation of the Recombination Epoch","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Dimitar D. Sasselov, Douglas Scott, Sara Seager","submitted_at":"1999-09-15T19:28:51Z","abstract_excerpt":"We have developed an improved recombination calculation of H, HeI, and HeII in the early Universe which involves a line-by-line treatment of each atomic level. We find two major differences compared with previous calculations. Firstly, the ionization fraction x_e is approximately 10% smaller for redshifts <~800, due to non-equilibrium processes in the excited states of H. Secondly, HeI recombination is much slower than previously thought, and is delayed until just before H recombines. We describe the basic physics behind the new results and present a simple way to reproduce our calculation. Th"},"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":"astro-ph/9909275","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"1999-09-15T19:28:51Z","cross_cats_sorted":[],"title_canon_sha256":"ff6b262a043348ed24e271a4e6fe8a62c85d876b6dcd28190379e7c26d132208","abstract_canon_sha256":"0bd64fbb0c616027125b014f68a6ce014dea34d8e0747935a661b2afce8cb1d4"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T15:51:15.275194Z","signature_b64":"ZVR19zKWieQv2Qx4cMbnyJxlKfKpgKx1GreA/d81E1pGijxbanss7psuhLtMV/zjha1GJV4O9jjC/1oTy6vJBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"94769882b47888a61f6fc3ab6e6d0f61f08e8a0db844e476671d0a371f933262","last_reissued_at":"2026-07-04T15:51:15.274796Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T15:51:15.274796Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"A New Calculation of the Recombination Epoch","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Dimitar D. Sasselov, Douglas Scott, Sara Seager","submitted_at":"1999-09-15T19:28:51Z","abstract_excerpt":"We have developed an improved recombination calculation of H, HeI, and HeII in the early Universe which involves a line-by-line treatment of each atomic level. We find two major differences compared with previous calculations. Firstly, the ionization fraction x_e is approximately 10% smaller for redshifts <~800, due to non-equilibrium processes in the excited states of H. Secondly, HeI recombination is much slower than previously thought, and is delayed until just before H recombines. We describe the basic physics behind the new results and present a simple way to reproduce our calculation. Th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9909275","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/astro-ph/9909275/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/9909275","created_at":"2026-07-04T15:51:15.274863+00:00"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/9909275v2","created_at":"2026-07-04T15:51:15.274863+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/9909275","created_at":"2026-07-04T15:51:15.274863+00:00"},{"alias_kind":"pith_short_12","alias_value":"SR3JRAVUPCEK","created_at":"2026-07-04T15:51:15.274863+00:00"},{"alias_kind":"pith_short_16","alias_value":"SR3JRAVUPCEKMH3P","created_at":"2026-07-04T15:51:15.274863+00:00"},{"alias_kind":"pith_short_8","alias_value":"SR3JRAVU","created_at":"2026-07-04T15:51:15.274863+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":5,"internal_anchor_count":4,"sample":[{"citing_arxiv_id":"2606.05853","citing_title":"Reconstructing dark energy with fewer assumptions","ref_index":99,"is_internal_anchor":true},{"citing_arxiv_id":"1907.04324","citing_title":"Dark Matter Energy Deposition and Production from the Table-Top to the Cosmos","ref_index":125,"is_internal_anchor":true},{"citing_arxiv_id":"1907.06485","citing_title":"CMB constraints on ultra-light primordial black holes with extended mass distributions","ref_index":39,"is_internal_anchor":true},{"citing_arxiv_id":"2507.10101","citing_title":"Comparative Study of Early-Universe Epochs in an $f(R,L_m)$ Gravity Model with Effective Curvature--Matter Interaction and $\\Lambda$CDM Cosmology","ref_index":26,"is_internal_anchor":true},{"citing_arxiv_id":"2604.17083","citing_title":"Dark ages bounds on non-accreting massive compact halo objects","ref_index":121,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH","json":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH.json","graph_json":"https://pith.science/api/pith-number/SR3JRAVUPCEKMH3PYOVW43IPMH/graph.json","events_json":"https://pith.science/api/pith-number/SR3JRAVUPCEKMH3PYOVW43IPMH/events.json","paper":"https://pith.science/paper/SR3JRAVU"},"agent_actions":{"view_html":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH","download_json":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH.json","view_paper":"https://pith.science/paper/SR3JRAVU","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=astro-ph/9909275&json=true","fetch_graph":"https://pith.science/api/pith-number/SR3JRAVUPCEKMH3PYOVW43IPMH/graph.json","fetch_events":"https://pith.science/api/pith-number/SR3JRAVUPCEKMH3PYOVW43IPMH/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH/action/timestamp_anchor","attest_storage":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH/action/storage_attestation","attest_author":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH/action/author_attestation","sign_citation":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH/action/citation_signature","submit_replication":"https://pith.science/pith/SR3JRAVUPCEKMH3PYOVW43IPMH/action/replication_record"}},"created_at":"2026-07-04T15:51:15.274863+00:00","updated_at":"2026-07-04T15:51:15.274863+00:00"}