{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2014:MBHZOLBDWOVCR3G365HY6QX4QL","short_pith_number":"pith:MBHZOLBD","schema_version":"1.0","canonical_sha256":"604f972c23b3aa28ecdbf74f8f42fc82c99253e68c9c2c83b31680da7ea7d516","source":{"kind":"arxiv","id":"1404.0887","version":4},"attestation_state":"computed","paper":{"title":"Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged \\lambda 21 cm Signal at z~20","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"G. Bernardi, L.J. Greenhill, M. McQuinn","submitted_at":"2014-04-03T12:50:42Z","abstract_excerpt":"The most promising near-term observable of the cosmic dark age prior to widespread reionization (z~15-200) is the sky-averaged \\lambda 21 cm background arising from hydrogen in the intergalactic medium. Though an individual antenna could in principle detect the line signature, data analysis must separate foregrounds that are orders of magnitude brighter than the \\lambda 21 cm background (but that are anticipated to vary monotonically and gradually with frequency). Using more physically motivated models for foregrounds than in previous studies, we show that the intrinsic \"spectral smoothness\" o"},"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":"1404.0887","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2014-04-03T12:50:42Z","cross_cats_sorted":[],"title_canon_sha256":"fdcee838179477919c42b3d1c9e9cf8ea4cbae8d640bbe1a33cd6d6340c77dc4","abstract_canon_sha256":"fb743073f915d45f510293da6a755ead1916241e2cc0b164afb1b4edd0bb140e"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:43:42.637007Z","signature_b64":"AGKES4u4/C0sMU9y0Rr0Y1zfmfP+N0weG03XrksO5ZIFMSCG/iwAYpp6gtFEe7v5/W86190L7p53dvCt0CLTBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"604f972c23b3aa28ecdbf74f8f42fc82c99253e68c9c2c83b31680da7ea7d516","last_reissued_at":"2026-05-18T01:43:42.636566Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:43:42.636566Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged \\lambda 21 cm Signal at z~20","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"G. Bernardi, L.J. Greenhill, M. McQuinn","submitted_at":"2014-04-03T12:50:42Z","abstract_excerpt":"The most promising near-term observable of the cosmic dark age prior to widespread reionization (z~15-200) is the sky-averaged \\lambda 21 cm background arising from hydrogen in the intergalactic medium. Though an individual antenna could in principle detect the line signature, data analysis must separate foregrounds that are orders of magnitude brighter than the \\lambda 21 cm background (but that are anticipated to vary monotonically and gradually with frequency). Using more physically motivated models for foregrounds than in previous studies, we show that the intrinsic \"spectral smoothness\" o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1404.0887","kind":"arxiv","version":4},"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":"1404.0887","created_at":"2026-05-18T01:43:42.636635+00:00"},{"alias_kind":"arxiv_version","alias_value":"1404.0887v4","created_at":"2026-05-18T01:43:42.636635+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1404.0887","created_at":"2026-05-18T01:43:42.636635+00:00"},{"alias_kind":"pith_short_12","alias_value":"MBHZOLBDWOVC","created_at":"2026-05-18T12:28:38.356838+00:00"},{"alias_kind":"pith_short_16","alias_value":"MBHZOLBDWOVCR3G3","created_at":"2026-05-18T12:28:38.356838+00:00"},{"alias_kind":"pith_short_8","alias_value":"MBHZOLBD","created_at":"2026-05-18T12:28:38.356838+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/MBHZOLBDWOVCR3G365HY6QX4QL","json":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL.json","graph_json":"https://pith.science/api/pith-number/MBHZOLBDWOVCR3G365HY6QX4QL/graph.json","events_json":"https://pith.science/api/pith-number/MBHZOLBDWOVCR3G365HY6QX4QL/events.json","paper":"https://pith.science/paper/MBHZOLBD"},"agent_actions":{"view_html":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL","download_json":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL.json","view_paper":"https://pith.science/paper/MBHZOLBD","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1404.0887&json=true","fetch_graph":"https://pith.science/api/pith-number/MBHZOLBDWOVCR3G365HY6QX4QL/graph.json","fetch_events":"https://pith.science/api/pith-number/MBHZOLBDWOVCR3G365HY6QX4QL/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL/action/timestamp_anchor","attest_storage":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL/action/storage_attestation","attest_author":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL/action/author_attestation","sign_citation":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL/action/citation_signature","submit_replication":"https://pith.science/pith/MBHZOLBDWOVCR3G365HY6QX4QL/action/replication_record"}},"created_at":"2026-05-18T01:43:42.636635+00:00","updated_at":"2026-05-18T01:43:42.636635+00:00"}