{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:I5TDXJGTEQLKNWVGIYUITWJVLT","short_pith_number":"pith:I5TDXJGT","canonical_record":{"source":{"id":"1510.00271","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-10-01T15:05:02Z","cross_cats_sorted":[],"title_canon_sha256":"2fcc9ee70c74042c98ae731ccb8600875a6523aa7febbfb01a50fd323e5319d5","abstract_canon_sha256":"a22d8a6b21fd20c1f282f4315d22fb27ecb146c965fc94c3d95edad7125ac660"},"schema_version":"1.0"},"canonical_sha256":"47663ba4d32416a6daa6462889d9355cc1a64a70f09f8f7a4f55cb7fcbc36540","source":{"kind":"arxiv","id":"1510.00271","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1510.00271","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"arxiv_version","alias_value":"1510.00271v2","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1510.00271","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"pith_short_12","alias_value":"I5TDXJGTEQLK","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_16","alias_value":"I5TDXJGTEQLKNWVG","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_8","alias_value":"I5TDXJGT","created_at":"2026-05-18T12:29:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:I5TDXJGTEQLKNWVGIYUITWJVLT","target":"record","payload":{"canonical_record":{"source":{"id":"1510.00271","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-10-01T15:05:02Z","cross_cats_sorted":[],"title_canon_sha256":"2fcc9ee70c74042c98ae731ccb8600875a6523aa7febbfb01a50fd323e5319d5","abstract_canon_sha256":"a22d8a6b21fd20c1f282f4315d22fb27ecb146c965fc94c3d95edad7125ac660"},"schema_version":"1.0"},"canonical_sha256":"47663ba4d32416a6daa6462889d9355cc1a64a70f09f8f7a4f55cb7fcbc36540","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:25:24.289185Z","signature_b64":"Yd5h66I8FLWdqAOVNLbDhp1w7YWukuSwbUKmoG/MHXAjAM4T41PDDTCGiQ93iL89uhJRj83MTXiXYqNfn5QHCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"47663ba4d32416a6daa6462889d9355cc1a64a70f09f8f7a4f55cb7fcbc36540","last_reissued_at":"2026-05-18T01:25:24.288733Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:25:24.288733Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1510.00271","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:25:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6ySRUpS6GChoSXqGq6zfaXFB874djX5ggs2Y7bSsCANPRdCmZbTHd0xSdobiWS1BYB+HuOX8cQjXegaw1RbcBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T19:07:52.576873Z"},"content_sha256":"6663d037dbcaab12ac9a8f951108c58c082fab33360a4c30aeb7f6f18080e07e","schema_version":"1.0","event_id":"sha256:6663d037dbcaab12ac9a8f951108c58c082fab33360a4c30aeb7f6f18080e07e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:I5TDXJGTEQLKNWVGIYUITWJVLT","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Parametrizations of the global 21-cm signal and parameter estimation from single-dipole experiments","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"(2) University of Colorado, (3) Imperial College London), Geraint J. A. Harker (1), Jack O. Burns (2), Jonathan R. Pritchard (3) ((1) University College London, Jordan Mirocha (2)","submitted_at":"2015-10-01T15:05:02Z","abstract_excerpt":"One approach to extracting the global 21-cm signal from total-power measurements at low radio frequencies is to parametrize the different contributions to the data and then fit for these parameters. We examine parametrizations of the 21-cm signal itself, and propose one based on modelling the Lyman-alpha background, IGM temperature and hydrogen ionized fraction using tanh functions. This captures the shape of the signal from a physical modelling code better than an earlier parametrization based on interpolating between maxima and minima of the signal, and imposes a greater level of physical pl"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1510.00271","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:25:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"vV2haZz4Ew7iWhA/OKsmwfnyOvsp30kDtD03nwzmXOz/3L75DDl2ttDoJdCJxceHUmemMFQt6pmISppeLALHDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T19:07:52.577220Z"},"content_sha256":"46127d163bf95d9e6ae4652fd595f5c70a1ea65c641a1a3bf9d6e87996c9f1ce","schema_version":"1.0","event_id":"sha256:46127d163bf95d9e6ae4652fd595f5c70a1ea65c641a1a3bf9d6e87996c9f1ce"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/bundle.json","state_url":"https://pith.science/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-03T19:07:52Z","links":{"resolver":"https://pith.science/pith/I5TDXJGTEQLKNWVGIYUITWJVLT","bundle":"https://pith.science/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/bundle.json","state":"https://pith.science/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/state.json","well_known_bundle":"https://pith.science/.well-known/pith/I5TDXJGTEQLKNWVGIYUITWJVLT/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:I5TDXJGTEQLKNWVGIYUITWJVLT","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"a22d8a6b21fd20c1f282f4315d22fb27ecb146c965fc94c3d95edad7125ac660","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-10-01T15:05:02Z","title_canon_sha256":"2fcc9ee70c74042c98ae731ccb8600875a6523aa7febbfb01a50fd323e5319d5"},"schema_version":"1.0","source":{"id":"1510.00271","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1510.00271","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"arxiv_version","alias_value":"1510.00271v2","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1510.00271","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"pith_short_12","alias_value":"I5TDXJGTEQLK","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_16","alias_value":"I5TDXJGTEQLKNWVG","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_8","alias_value":"I5TDXJGT","created_at":"2026-05-18T12:29:25Z"}],"graph_snapshots":[{"event_id":"sha256:46127d163bf95d9e6ae4652fd595f5c70a1ea65c641a1a3bf9d6e87996c9f1ce","target":"graph","created_at":"2026-05-18T01:25:24Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"One approach to extracting the global 21-cm signal from total-power measurements at low radio frequencies is to parametrize the different contributions to the data and then fit for these parameters. We examine parametrizations of the 21-cm signal itself, and propose one based on modelling the Lyman-alpha background, IGM temperature and hydrogen ionized fraction using tanh functions. This captures the shape of the signal from a physical modelling code better than an earlier parametrization based on interpolating between maxima and minima of the signal, and imposes a greater level of physical pl","authors_text":"(2) University of Colorado, (3) Imperial College London), Geraint J. A. Harker (1), Jack O. Burns (2), Jonathan R. Pritchard (3) ((1) University College London, Jordan Mirocha (2)","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-10-01T15:05:02Z","title":"Parametrizations of the global 21-cm signal and parameter estimation from single-dipole experiments"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1510.00271","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:6663d037dbcaab12ac9a8f951108c58c082fab33360a4c30aeb7f6f18080e07e","target":"record","created_at":"2026-05-18T01:25:24Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"a22d8a6b21fd20c1f282f4315d22fb27ecb146c965fc94c3d95edad7125ac660","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-10-01T15:05:02Z","title_canon_sha256":"2fcc9ee70c74042c98ae731ccb8600875a6523aa7febbfb01a50fd323e5319d5"},"schema_version":"1.0","source":{"id":"1510.00271","kind":"arxiv","version":2}},"canonical_sha256":"47663ba4d32416a6daa6462889d9355cc1a64a70f09f8f7a4f55cb7fcbc36540","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"47663ba4d32416a6daa6462889d9355cc1a64a70f09f8f7a4f55cb7fcbc36540","first_computed_at":"2026-05-18T01:25:24.288733Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:25:24.288733Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Yd5h66I8FLWdqAOVNLbDhp1w7YWukuSwbUKmoG/MHXAjAM4T41PDDTCGiQ93iL89uhJRj83MTXiXYqNfn5QHCg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:25:24.289185Z","signed_message":"canonical_sha256_bytes"},"source_id":"1510.00271","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6663d037dbcaab12ac9a8f951108c58c082fab33360a4c30aeb7f6f18080e07e","sha256:46127d163bf95d9e6ae4652fd595f5c70a1ea65c641a1a3bf9d6e87996c9f1ce"],"state_sha256":"f67e4ffdcad0addcc0cf351b11f690b5792bde6d0429c0dbcfb2da7f2b8ccd65"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"oHTYX94270wALVukPnHe+aUb945P0Pqk6HT6u+y1vo19Nz1bTqLvxVQ03nZrZ834jfJNUOydwyE7usQqjHkkBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T19:07:52.579338Z","bundle_sha256":"315664d5dc1889157fe2dbb60950486a02d90c87b6fff79ac9d0dc19c9e712e1"}}