{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:QWH2QSIOLMN74IJGYJ4YPE7GX7","short_pith_number":"pith:QWH2QSIO","canonical_record":{"source":{"id":"2004.03701","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2020-04-07T20:47:34Z","cross_cats_sorted":[],"title_canon_sha256":"e4ba370a13c0ef8456a0b5c2495b0677317c1923ced638e7fc50a1e4dc11db3d","abstract_canon_sha256":"f1080264cbd2fc8b3ffd4c37914879cb528d24206cc0789eb97beabb25f34f12"},"schema_version":"1.0"},"canonical_sha256":"858fa8490e5b1bfe2126c2798793e6bfed9a113d87b572300afe9b26b18c5425","source":{"kind":"arxiv","id":"2004.03701","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2004.03701","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"arxiv_version","alias_value":"2004.03701v2","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2004.03701","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_12","alias_value":"QWH2QSIOLMN7","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_16","alias_value":"QWH2QSIOLMN74IJG","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_8","alias_value":"QWH2QSIO","created_at":"2026-07-05T01:26:12Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:QWH2QSIOLMN74IJGYJ4YPE7GX7","target":"record","payload":{"canonical_record":{"source":{"id":"2004.03701","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2020-04-07T20:47:34Z","cross_cats_sorted":[],"title_canon_sha256":"e4ba370a13c0ef8456a0b5c2495b0677317c1923ced638e7fc50a1e4dc11db3d","abstract_canon_sha256":"f1080264cbd2fc8b3ffd4c37914879cb528d24206cc0789eb97beabb25f34f12"},"schema_version":"1.0"},"canonical_sha256":"858fa8490e5b1bfe2126c2798793e6bfed9a113d87b572300afe9b26b18c5425","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:26:12.303293Z","signature_b64":"dpgnNcdgUwNb0qiQwSoD00bkDfCHjAdEkQAa1vUCyfu3a/+T0o/75ZfI2epJOPCzwzA5Q2DrBNcRze3Ux4SKBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"858fa8490e5b1bfe2126c2798793e6bfed9a113d87b572300afe9b26b18c5425","last_reissued_at":"2026-07-05T01:26:12.302846Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:26:12.302846Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2004.03701","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":"2026-07-05T01:26:12Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"D0YX/H1vXSQwGqguUVN9Z1o2U+FdcIpzqHSx+mY/bowp/Mg82ahqjEw044lpDr3vt2ZTq68XYxITP0kKrtWyBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-12T12:24:01.538481Z"},"content_sha256":"6ebc4f85d76c750ee6c0a3253dce3f2ec9e1a4aeb45187a2850f4b3447af3f03","schema_version":"1.0","event_id":"sha256:6ebc4f85d76c750ee6c0a3253dce3f2ec9e1a4aeb45187a2850f4b3447af3f03"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:QWH2QSIOLMN74IJGYJ4YPE7GX7","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Optimal periodicity searching: Revisiting the Fast Folding Algorithm for large-scale pulsar surveys","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"A.G. Lyne, B.W. Stappers, E.D. Barr, E.F. Keane, V. Morello","submitted_at":"2020-04-07T20:47:34Z","abstract_excerpt":"The Fast Folding Algorithm (FFA) is a phase-coherent search technique for periodic signals. It has rarely been used in radio pulsar searches, having been historically supplanted by the less computationally expensive Fast Fourier Transform (FFT) with incoherent harmonic summing (IHS). Here we derive from first principles that an FFA search closely approaches the theoretical optimum sensitivity to all periodic signals; it is analytically shown to be significantly more sensitive than the standard FFT+IHS method, regardless of pulse period and duty cycle. A portion of the pulsar phase space has th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2004.03701","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/2004.03701/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:26:12Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"eqcXAnB/Oj1+jedr91vW5iqlGk3IX/LbNdFRdeUdY5XTk9iew/ARSz6HyW2Rl8UyVTYLg94OUrNRE4HufE9UBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-12T12:24:01.539109Z"},"content_sha256":"13c26111bb649325732c45500002a50f81e7b6e7b7dbf81a0864a55f91fad067","schema_version":"1.0","event_id":"sha256:13c26111bb649325732c45500002a50f81e7b6e7b7dbf81a0864a55f91fad067"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/bundle.json","state_url":"https://pith.science/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/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":"2026-08-12T12:24:01Z","links":{"resolver":"https://pith.science/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7","bundle":"https://pith.science/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/bundle.json","state":"https://pith.science/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QWH2QSIOLMN74IJGYJ4YPE7GX7/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:QWH2QSIOLMN74IJGYJ4YPE7GX7","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":"f1080264cbd2fc8b3ffd4c37914879cb528d24206cc0789eb97beabb25f34f12","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2020-04-07T20:47:34Z","title_canon_sha256":"e4ba370a13c0ef8456a0b5c2495b0677317c1923ced638e7fc50a1e4dc11db3d"},"schema_version":"1.0","source":{"id":"2004.03701","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2004.03701","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"arxiv_version","alias_value":"2004.03701v2","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2004.03701","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_12","alias_value":"QWH2QSIOLMN7","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_16","alias_value":"QWH2QSIOLMN74IJG","created_at":"2026-07-05T01:26:12Z"},{"alias_kind":"pith_short_8","alias_value":"QWH2QSIO","created_at":"2026-07-05T01:26:12Z"}],"graph_snapshots":[{"event_id":"sha256:13c26111bb649325732c45500002a50f81e7b6e7b7dbf81a0864a55f91fad067","target":"graph","created_at":"2026-07-05T01:26:12Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2004.03701/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The Fast Folding Algorithm (FFA) is a phase-coherent search technique for periodic signals. It has rarely been used in radio pulsar searches, having been historically supplanted by the less computationally expensive Fast Fourier Transform (FFT) with incoherent harmonic summing (IHS). Here we derive from first principles that an FFA search closely approaches the theoretical optimum sensitivity to all periodic signals; it is analytically shown to be significantly more sensitive than the standard FFT+IHS method, regardless of pulse period and duty cycle. A portion of the pulsar phase space has th","authors_text":"A.G. Lyne, B.W. Stappers, E.D. Barr, E.F. Keane, V. Morello","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2020-04-07T20:47:34Z","title":"Optimal periodicity searching: Revisiting the Fast Folding Algorithm for large-scale pulsar surveys"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2004.03701","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":"sha256:6ebc4f85d76c750ee6c0a3253dce3f2ec9e1a4aeb45187a2850f4b3447af3f03","target":"record","created_at":"2026-07-05T01:26:12Z","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":"f1080264cbd2fc8b3ffd4c37914879cb528d24206cc0789eb97beabb25f34f12","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2020-04-07T20:47:34Z","title_canon_sha256":"e4ba370a13c0ef8456a0b5c2495b0677317c1923ced638e7fc50a1e4dc11db3d"},"schema_version":"1.0","source":{"id":"2004.03701","kind":"arxiv","version":2}},"canonical_sha256":"858fa8490e5b1bfe2126c2798793e6bfed9a113d87b572300afe9b26b18c5425","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"858fa8490e5b1bfe2126c2798793e6bfed9a113d87b572300afe9b26b18c5425","first_computed_at":"2026-07-05T01:26:12.302846Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:26:12.302846Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"dpgnNcdgUwNb0qiQwSoD00bkDfCHjAdEkQAa1vUCyfu3a/+T0o/75ZfI2epJOPCzwzA5Q2DrBNcRze3Ux4SKBA==","signature_status":"signed_v1","signed_at":"2026-07-05T01:26:12.303293Z","signed_message":"canonical_sha256_bytes"},"source_id":"2004.03701","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6ebc4f85d76c750ee6c0a3253dce3f2ec9e1a4aeb45187a2850f4b3447af3f03","sha256:13c26111bb649325732c45500002a50f81e7b6e7b7dbf81a0864a55f91fad067"],"state_sha256":"68f8e3e0c8eb7a4d8d37d1ced49bff44afe5d5917cfd52ca87050b6feffbf312"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tNSCmXX4iHqn93OD3pD3uJsQwqcWc2hiQ0EEzgJUMgOj7OW/BYmzBKjkQ0fqwjbcXwP0euJfP+6lPtFd5v1qBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-12T12:24:01.543113Z","bundle_sha256":"f1e7c729c0908fbb9c33f5ffa33dc71b469c3286aa84bce825d1ceb395b1e885"}}