{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:7VE5RVLQPBYCECPO66XVGTO4Y4","short_pith_number":"pith:7VE5RVLQ","canonical_record":{"source":{"id":"1908.08472","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-22T16:09:19Z","cross_cats_sorted":["astro-ph.CO","hep-th"],"title_canon_sha256":"613b9a39a78c57622a396ba6d7aef53b0ee05343d8cf5052fb06004b1417fc6e","abstract_canon_sha256":"20c4858635609cc3cfdcdde1f6e57fbe82e1f3d58459252c8cf820cb44d262b8"},"schema_version":"1.0"},"canonical_sha256":"fd49d8d57078702209eef7af534ddcc730de6be4895532d55236fdff80661996","source":{"kind":"arxiv","id":"1908.08472","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1908.08472","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"arxiv_version","alias_value":"1908.08472v2","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1908.08472","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_12","alias_value":"7VE5RVLQPBYC","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_16","alias_value":"7VE5RVLQPBYCECPO","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_8","alias_value":"7VE5RVLQ","created_at":"2026-07-05T00:55:17Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:7VE5RVLQPBYCECPO66XVGTO4Y4","target":"record","payload":{"canonical_record":{"source":{"id":"1908.08472","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-22T16:09:19Z","cross_cats_sorted":["astro-ph.CO","hep-th"],"title_canon_sha256":"613b9a39a78c57622a396ba6d7aef53b0ee05343d8cf5052fb06004b1417fc6e","abstract_canon_sha256":"20c4858635609cc3cfdcdde1f6e57fbe82e1f3d58459252c8cf820cb44d262b8"},"schema_version":"1.0"},"canonical_sha256":"fd49d8d57078702209eef7af534ddcc730de6be4895532d55236fdff80661996","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:55:17.801624Z","signature_b64":"Drw65n3IgEv/3tGLmgijtntEyXS4u2s28Nlu7eQOERpsVhZvlUCPJqzQr04QKbvlaTS93QE4Y37VORbMGXgEDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fd49d8d57078702209eef7af534ddcc730de6be4895532d55236fdff80661996","last_reissued_at":"2026-07-05T00:55:17.801213Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:55:17.801213Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1908.08472","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":"2026-07-05T00:55:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1o4t8UitvIp9DnseF5nzwgNv9SX/LrFpkWqAurI7MUZFKbWcnKEU15EQ9XcGFqbj8+nQIg/VFrVgUdLqELy4AA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-16T12:24:26.210106Z"},"content_sha256":"3924588c0a0bafd31c147aba7b485951dfafc3bb093c914905c38c3c9b49746f","schema_version":"1.0","event_id":"sha256:3924588c0a0bafd31c147aba7b485951dfafc3bb093c914905c38c3c9b49746f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:7VE5RVLQPBYCECPO66XVGTO4Y4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Measuring $H_0$ with pulsar timing arrays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","hep-th"],"primary_cat":"gr-qc","authors_text":"Dom\\`enec Espriu, Luciano Gabbanelli, Marc Rodoreda","submitted_at":"2019-08-22T16:09:19Z","abstract_excerpt":"Pulsar Timing Arrays have yet to convincingly observe gravitational waves. Some time ago it was pointed out by one of the authors that a dramatic enhancement of the signal would take place for particular values of the angle subtended by the source and the observed pulsar. This enhancement is due to the fact that waves propagate in a Friedmann-Lemaitre-Robertson-Walker metric where, contrary to some wide-spread belief, a simple harmonic function with a red-shifted frequency is not a solution of the equation of motion. At the first non-trivial order, proper solutions have an effective wave numbe"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1908.08472","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/1908.08472/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":"2026-07-05T00:55:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6MLQqVhM7uM808hpcdQMz+aaFRpdHoWESbSwDWxG5lu55XfkRe6BOUHQIiCOQuWcnL5W117LN6fDE+uud0ioAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-16T12:24:26.210668Z"},"content_sha256":"15a8427ec8717d8e15b830158098f260c5c05d1f82dc34067f253bfc1c5c1599","schema_version":"1.0","event_id":"sha256:15a8427ec8717d8e15b830158098f260c5c05d1f82dc34067f253bfc1c5c1599"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/bundle.json","state_url":"https://pith.science/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/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":"2026-08-16T12:24:26Z","links":{"resolver":"https://pith.science/pith/7VE5RVLQPBYCECPO66XVGTO4Y4","bundle":"https://pith.science/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/bundle.json","state":"https://pith.science/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7VE5RVLQPBYCECPO66XVGTO4Y4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:7VE5RVLQPBYCECPO66XVGTO4Y4","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":"20c4858635609cc3cfdcdde1f6e57fbe82e1f3d58459252c8cf820cb44d262b8","cross_cats_sorted":["astro-ph.CO","hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-22T16:09:19Z","title_canon_sha256":"613b9a39a78c57622a396ba6d7aef53b0ee05343d8cf5052fb06004b1417fc6e"},"schema_version":"1.0","source":{"id":"1908.08472","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1908.08472","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"arxiv_version","alias_value":"1908.08472v2","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1908.08472","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_12","alias_value":"7VE5RVLQPBYC","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_16","alias_value":"7VE5RVLQPBYCECPO","created_at":"2026-07-05T00:55:17Z"},{"alias_kind":"pith_short_8","alias_value":"7VE5RVLQ","created_at":"2026-07-05T00:55:17Z"}],"graph_snapshots":[{"event_id":"sha256:15a8427ec8717d8e15b830158098f260c5c05d1f82dc34067f253bfc1c5c1599","target":"graph","created_at":"2026-07-05T00:55:17Z","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/1908.08472/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Pulsar Timing Arrays have yet to convincingly observe gravitational waves. Some time ago it was pointed out by one of the authors that a dramatic enhancement of the signal would take place for particular values of the angle subtended by the source and the observed pulsar. This enhancement is due to the fact that waves propagate in a Friedmann-Lemaitre-Robertson-Walker metric where, contrary to some wide-spread belief, a simple harmonic function with a red-shifted frequency is not a solution of the equation of motion. At the first non-trivial order, proper solutions have an effective wave numbe","authors_text":"Dom\\`enec Espriu, Luciano Gabbanelli, Marc Rodoreda","cross_cats":["astro-ph.CO","hep-th"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-22T16:09:19Z","title":"Measuring $H_0$ with pulsar timing arrays"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1908.08472","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":"sha256:3924588c0a0bafd31c147aba7b485951dfafc3bb093c914905c38c3c9b49746f","target":"record","created_at":"2026-07-05T00:55:17Z","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":"20c4858635609cc3cfdcdde1f6e57fbe82e1f3d58459252c8cf820cb44d262b8","cross_cats_sorted":["astro-ph.CO","hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-22T16:09:19Z","title_canon_sha256":"613b9a39a78c57622a396ba6d7aef53b0ee05343d8cf5052fb06004b1417fc6e"},"schema_version":"1.0","source":{"id":"1908.08472","kind":"arxiv","version":2}},"canonical_sha256":"fd49d8d57078702209eef7af534ddcc730de6be4895532d55236fdff80661996","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fd49d8d57078702209eef7af534ddcc730de6be4895532d55236fdff80661996","first_computed_at":"2026-07-05T00:55:17.801213Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:55:17.801213Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Drw65n3IgEv/3tGLmgijtntEyXS4u2s28Nlu7eQOERpsVhZvlUCPJqzQr04QKbvlaTS93QE4Y37VORbMGXgEDw==","signature_status":"signed_v1","signed_at":"2026-07-05T00:55:17.801624Z","signed_message":"canonical_sha256_bytes"},"source_id":"1908.08472","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:3924588c0a0bafd31c147aba7b485951dfafc3bb093c914905c38c3c9b49746f","sha256:15a8427ec8717d8e15b830158098f260c5c05d1f82dc34067f253bfc1c5c1599"],"state_sha256":"2224b226c3119265dcc8cf1af42d5e92c259aa4c8eff23951a589e00a11486c7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"izW33hApfUKnJe4JvsUhv3XL2yumqI7noEO15tDRgTtEozT1CU1WUPNKZbHeOiuW/q/3EiBJHT/LfrxzQ/mICQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-16T12:24:26.216273Z","bundle_sha256":"559ae0e96346502b104ac941e5c513c557818a21769ff594ab6af226ba2789ae"}}