{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:JWOC2H3I2OC6RTNSJBOTBTCZWN","short_pith_number":"pith:JWOC2H3I","canonical_record":{"source":{"id":"1511.07869","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-24T21:00:00Z","cross_cats_sorted":["astro-ph.GA","gr-qc"],"title_canon_sha256":"feceeb4a3cfd0bc7d0f17657d60764c91402cba30b628712b672c6d7a17f017f","abstract_canon_sha256":"65ce9c6d4a2c26b25d18a3048b76f5909d41a6e9be38e4f870c00c4dbcc8b288"},"schema_version":"1.0"},"canonical_sha256":"4d9c2d1f68d385e8cdb2485d30cc59b35f291aa2301844c5da0c939f1365dff9","source":{"kind":"arxiv","id":"1511.07869","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1511.07869","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"arxiv_version","alias_value":"1511.07869v1","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1511.07869","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"pith_short_12","alias_value":"JWOC2H3I2OC6","created_at":"2026-05-18T12:29:27Z"},{"alias_kind":"pith_short_16","alias_value":"JWOC2H3I2OC6RTNS","created_at":"2026-05-18T12:29:27Z"},{"alias_kind":"pith_short_8","alias_value":"JWOC2H3I","created_at":"2026-05-18T12:29:27Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:JWOC2H3I2OC6RTNSJBOTBTCZWN","target":"record","payload":{"canonical_record":{"source":{"id":"1511.07869","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-24T21:00:00Z","cross_cats_sorted":["astro-ph.GA","gr-qc"],"title_canon_sha256":"feceeb4a3cfd0bc7d0f17657d60764c91402cba30b628712b672c6d7a17f017f","abstract_canon_sha256":"65ce9c6d4a2c26b25d18a3048b76f5909d41a6e9be38e4f870c00c4dbcc8b288"},"schema_version":"1.0"},"canonical_sha256":"4d9c2d1f68d385e8cdb2485d30cc59b35f291aa2301844c5da0c939f1365dff9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:26:02.319028Z","signature_b64":"EzfsgT8cPaiSZoIodaC+VJxrKEL/Mvwesus+tphTkQeOiTkKSZRsNwSo9kYcNL1eSzO+Xm93VMly4X+JsdvTAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"4d9c2d1f68d385e8cdb2485d30cc59b35f291aa2301844c5da0c939f1365dff9","last_reissued_at":"2026-05-18T01:26:02.318373Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:26:02.318373Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1511.07869","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:26:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WpCWp8ztsDV1r8qdXnLjX5VTHqhIDmJCBbsGN1eqGYxupBnQ4pvkhrlPtUGufNfvMibbq3yRgEyzh+bNJvi+DA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T12:36:19.488000Z"},"content_sha256":"8b292a6388a13026d630e76ee1d93c477562a9961c2b55c126b534ddddcdf9f0","schema_version":"1.0","event_id":"sha256:8b292a6388a13026d630e76ee1d93c477562a9961c2b55c126b534ddddcdf9f0"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:JWOC2H3I2OC6RTNSJBOTBTCZWN","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Gravitational-Wave Detection and Astrophysics with Pulsar Timing Arrays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.GA","gr-qc"],"primary_cat":"astro-ph.IM","authors_text":"Sarah Burke-Spolaor","submitted_at":"2015-11-24T21:00:00Z","abstract_excerpt":"We have begun an exciting era for gravitational wave detection, as several world-leading experiments are breaching the threshold of anticipated signal strengths. Pulsar timing arrays (PTAs) are pan-Galactic gravitational wave detectors that are already cutting into the expected strength of gravitational waves from cosmic strings and binary supermassive black holes in the nHz-$\\mu$Hz gravitational wave band. These limits are leading to constraints on the evolutionary state of the Universe. Here, we provide a broad review of this field, from how pulsars are used as tools for detection, to astrop"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.07869","kind":"arxiv","version":1},"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":"2026-05-18T01:26:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"53g/5KMn07yvVMH9chote6AtP84VnqS4YUTSE+CA3J3QmaW9IJBmCC95uhNfcJF0fVEbYvL9K+JcgNVFY0o2Bw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T12:36:19.488760Z"},"content_sha256":"076af612865cf9bc607a1d9eb147ca2313165b7119e57f8bfaf163601619e1d7","schema_version":"1.0","event_id":"sha256:076af612865cf9bc607a1d9eb147ca2313165b7119e57f8bfaf163601619e1d7"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/bundle.json","state_url":"https://pith.science/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/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":"2026-05-31T12:36:19Z","links":{"resolver":"https://pith.science/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN","bundle":"https://pith.science/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/bundle.json","state":"https://pith.science/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/state.json","well_known_bundle":"https://pith.science/.well-known/pith/JWOC2H3I2OC6RTNSJBOTBTCZWN/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:JWOC2H3I2OC6RTNSJBOTBTCZWN","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":"65ce9c6d4a2c26b25d18a3048b76f5909d41a6e9be38e4f870c00c4dbcc8b288","cross_cats_sorted":["astro-ph.GA","gr-qc"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-24T21:00:00Z","title_canon_sha256":"feceeb4a3cfd0bc7d0f17657d60764c91402cba30b628712b672c6d7a17f017f"},"schema_version":"1.0","source":{"id":"1511.07869","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1511.07869","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"arxiv_version","alias_value":"1511.07869v1","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1511.07869","created_at":"2026-05-18T01:26:02Z"},{"alias_kind":"pith_short_12","alias_value":"JWOC2H3I2OC6","created_at":"2026-05-18T12:29:27Z"},{"alias_kind":"pith_short_16","alias_value":"JWOC2H3I2OC6RTNS","created_at":"2026-05-18T12:29:27Z"},{"alias_kind":"pith_short_8","alias_value":"JWOC2H3I","created_at":"2026-05-18T12:29:27Z"}],"graph_snapshots":[{"event_id":"sha256:076af612865cf9bc607a1d9eb147ca2313165b7119e57f8bfaf163601619e1d7","target":"graph","created_at":"2026-05-18T01:26:02Z","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":"We have begun an exciting era for gravitational wave detection, as several world-leading experiments are breaching the threshold of anticipated signal strengths. Pulsar timing arrays (PTAs) are pan-Galactic gravitational wave detectors that are already cutting into the expected strength of gravitational waves from cosmic strings and binary supermassive black holes in the nHz-$\\mu$Hz gravitational wave band. These limits are leading to constraints on the evolutionary state of the Universe. Here, we provide a broad review of this field, from how pulsars are used as tools for detection, to astrop","authors_text":"Sarah Burke-Spolaor","cross_cats":["astro-ph.GA","gr-qc"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-24T21:00:00Z","title":"Gravitational-Wave Detection and Astrophysics with Pulsar Timing Arrays"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.07869","kind":"arxiv","version":1},"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":"sha256:8b292a6388a13026d630e76ee1d93c477562a9961c2b55c126b534ddddcdf9f0","target":"record","created_at":"2026-05-18T01:26:02Z","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":"65ce9c6d4a2c26b25d18a3048b76f5909d41a6e9be38e4f870c00c4dbcc8b288","cross_cats_sorted":["astro-ph.GA","gr-qc"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2015-11-24T21:00:00Z","title_canon_sha256":"feceeb4a3cfd0bc7d0f17657d60764c91402cba30b628712b672c6d7a17f017f"},"schema_version":"1.0","source":{"id":"1511.07869","kind":"arxiv","version":1}},"canonical_sha256":"4d9c2d1f68d385e8cdb2485d30cc59b35f291aa2301844c5da0c939f1365dff9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4d9c2d1f68d385e8cdb2485d30cc59b35f291aa2301844c5da0c939f1365dff9","first_computed_at":"2026-05-18T01:26:02.318373Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:26:02.318373Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"EzfsgT8cPaiSZoIodaC+VJxrKEL/Mvwesus+tphTkQeOiTkKSZRsNwSo9kYcNL1eSzO+Xm93VMly4X+JsdvTAQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:26:02.319028Z","signed_message":"canonical_sha256_bytes"},"source_id":"1511.07869","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:8b292a6388a13026d630e76ee1d93c477562a9961c2b55c126b534ddddcdf9f0","sha256:076af612865cf9bc607a1d9eb147ca2313165b7119e57f8bfaf163601619e1d7"],"state_sha256":"4e749525ba4f48b5a71a18d0444cc4c23bb0489edd398add7394f3e768ea84b6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"fkNvfGEIuTwxzMdfwlYx2o1Wq1Uk8Etnoe3X6io8g6h4qVUSLSxymti4fAapbuJm6otkVYIfggiBgQJF3z6FAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T12:36:19.492906Z","bundle_sha256":"3e0e647e5490690ceb874f7e2e2e29fdf8699dd9194957c4303367519acf6613"}}