{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:PIO62QW7YNLHVDLGYW6EBB5OCI","short_pith_number":"pith:PIO62QW7","canonical_record":{"source":{"id":"2509.08041","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-09-09T18:00:00Z","cross_cats_sorted":["astro-ph.CO","astro-ph.HE"],"title_canon_sha256":"f306ce2f88f2468ee5df836eeb151ed6af12a383957577fd992e7a790dc6ed2d","abstract_canon_sha256":"9a4ac273a3a108521f30b0da932d50a5c99a9ba4e2d4544701ea5157d2e5cd52"},"schema_version":"1.0"},"canonical_sha256":"7a1ded42dfc3567a8d66c5bc4087ae1226cbdaf0b26c59756afb213bfadfa617","source":{"kind":"arxiv","id":"2509.08041","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2509.08041","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"arxiv_version","alias_value":"2509.08041v1","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2509.08041","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_12","alias_value":"PIO62QW7YNLH","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_16","alias_value":"PIO62QW7YNLHVDLG","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_8","alias_value":"PIO62QW7","created_at":"2026-07-05T12:08:10Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:PIO62QW7YNLHVDLGYW6EBB5OCI","target":"record","payload":{"canonical_record":{"source":{"id":"2509.08041","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-09-09T18:00:00Z","cross_cats_sorted":["astro-ph.CO","astro-ph.HE"],"title_canon_sha256":"f306ce2f88f2468ee5df836eeb151ed6af12a383957577fd992e7a790dc6ed2d","abstract_canon_sha256":"9a4ac273a3a108521f30b0da932d50a5c99a9ba4e2d4544701ea5157d2e5cd52"},"schema_version":"1.0"},"canonical_sha256":"7a1ded42dfc3567a8d66c5bc4087ae1226cbdaf0b26c59756afb213bfadfa617","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T12:08:10.266372Z","signature_b64":"bvA+EkseObljGcMs6sKWWRG0zVmT6Owinxz16A4ZRluKhWoKLDpQ5REDVbrvZMzCNSEvo6+wejhzCXFys0+eCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7a1ded42dfc3567a8d66c5bc4087ae1226cbdaf0b26c59756afb213bfadfa617","last_reissued_at":"2026-07-05T12:08:10.265821Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T12:08:10.265821Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2509.08041","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":"2026-07-05T12:08:10Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"+CaoKKfHhFmJmiv+cZEp07AiNlSWJKnej9uV/8FjOgwJX37CoQQlybxKT9CG5g8vT2Onxu9vMwb3VXdhBiY1BA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T03:11:09.870738Z"},"content_sha256":"6240db8e9b1d96c0ac38ec407c38096f682278e565592f8f4ada764dc63c01dd","schema_version":"1.0","event_id":"sha256:6240db8e9b1d96c0ac38ec407c38096f682278e565592f8f4ada764dc63c01dd"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:PIO62QW7YNLHVDLGYW6EBB5OCI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Uncertainties in the supermassive black hole abundance and implications for the GW background","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.CO","astro-ph.HE"],"primary_cat":"astro-ph.GA","authors_text":"Gabriela Sato-Polito, Matias Zaldarriaga","submitted_at":"2025-09-09T18:00:00Z","abstract_excerpt":"The present-day mass function of supermassive black holes is the most important observable quantity for the prediction and theoretical interpretation of the gravitational wave background (GWB) measured by pulsar timing arrays (PTAs). Due to the limited sample size of galaxies with dynamically inferred SMBH masses, more readily measurable galaxy properties $X$ that correlate with the black hole mass are used as labels (via scaling relations $M_{\\bullet}-X$), which can then be counted in a larger galaxy catalog to produce a measurement of the mass function. Estimating the amplitude of the GWB fr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2509.08041","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2509.08041/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":"2026-07-05T12:08:10Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Hgg7myuZNyA5tK7AJHpqy/IYWTsmgVDueyF3MdTfoTIYd1aCK6mq/rtsdUsahUlE1jBSgWg9mMQVlQfz5FIiDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T03:11:09.871818Z"},"content_sha256":"e125468e1e70a4ce4df50eb78b2f3c679aff726669a8213d8a70b0333717817b","schema_version":"1.0","event_id":"sha256:e125468e1e70a4ce4df50eb78b2f3c679aff726669a8213d8a70b0333717817b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/bundle.json","state_url":"https://pith.science/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/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":"2026-08-06T03:11:09Z","links":{"resolver":"https://pith.science/pith/PIO62QW7YNLHVDLGYW6EBB5OCI","bundle":"https://pith.science/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/bundle.json","state":"https://pith.science/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PIO62QW7YNLHVDLGYW6EBB5OCI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:PIO62QW7YNLHVDLGYW6EBB5OCI","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":"9a4ac273a3a108521f30b0da932d50a5c99a9ba4e2d4544701ea5157d2e5cd52","cross_cats_sorted":["astro-ph.CO","astro-ph.HE"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-09-09T18:00:00Z","title_canon_sha256":"f306ce2f88f2468ee5df836eeb151ed6af12a383957577fd992e7a790dc6ed2d"},"schema_version":"1.0","source":{"id":"2509.08041","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2509.08041","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"arxiv_version","alias_value":"2509.08041v1","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2509.08041","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_12","alias_value":"PIO62QW7YNLH","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_16","alias_value":"PIO62QW7YNLHVDLG","created_at":"2026-07-05T12:08:10Z"},{"alias_kind":"pith_short_8","alias_value":"PIO62QW7","created_at":"2026-07-05T12:08:10Z"}],"graph_snapshots":[{"event_id":"sha256:e125468e1e70a4ce4df50eb78b2f3c679aff726669a8213d8a70b0333717817b","target":"graph","created_at":"2026-07-05T12:08:10Z","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/2509.08041/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The present-day mass function of supermassive black holes is the most important observable quantity for the prediction and theoretical interpretation of the gravitational wave background (GWB) measured by pulsar timing arrays (PTAs). Due to the limited sample size of galaxies with dynamically inferred SMBH masses, more readily measurable galaxy properties $X$ that correlate with the black hole mass are used as labels (via scaling relations $M_{\\bullet}-X$), which can then be counted in a larger galaxy catalog to produce a measurement of the mass function. Estimating the amplitude of the GWB fr","authors_text":"Gabriela Sato-Polito, Matias Zaldarriaga","cross_cats":["astro-ph.CO","astro-ph.HE"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-09-09T18:00:00Z","title":"Uncertainties in the supermassive black hole abundance and implications for the GW background"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2509.08041","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":"sha256:6240db8e9b1d96c0ac38ec407c38096f682278e565592f8f4ada764dc63c01dd","target":"record","created_at":"2026-07-05T12:08:10Z","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":"9a4ac273a3a108521f30b0da932d50a5c99a9ba4e2d4544701ea5157d2e5cd52","cross_cats_sorted":["astro-ph.CO","astro-ph.HE"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-09-09T18:00:00Z","title_canon_sha256":"f306ce2f88f2468ee5df836eeb151ed6af12a383957577fd992e7a790dc6ed2d"},"schema_version":"1.0","source":{"id":"2509.08041","kind":"arxiv","version":1}},"canonical_sha256":"7a1ded42dfc3567a8d66c5bc4087ae1226cbdaf0b26c59756afb213bfadfa617","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7a1ded42dfc3567a8d66c5bc4087ae1226cbdaf0b26c59756afb213bfadfa617","first_computed_at":"2026-07-05T12:08:10.265821Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T12:08:10.265821Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"bvA+EkseObljGcMs6sKWWRG0zVmT6Owinxz16A4ZRluKhWoKLDpQ5REDVbrvZMzCNSEvo6+wejhzCXFys0+eCw==","signature_status":"signed_v1","signed_at":"2026-07-05T12:08:10.266372Z","signed_message":"canonical_sha256_bytes"},"source_id":"2509.08041","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6240db8e9b1d96c0ac38ec407c38096f682278e565592f8f4ada764dc63c01dd","sha256:e125468e1e70a4ce4df50eb78b2f3c679aff726669a8213d8a70b0333717817b"],"state_sha256":"8f6de7ac791e3e916452116104d3f651f9a112b329cb2188100d3b6a4cd5a37b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n1cJR1sXAOTcwRsu9Gn1O70G2DG10qbXvCHabdrVZqHvqdtqpsma5lIKj2MkClTkfQ4NgPXnb7RMsdp758rmBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-06T03:11:09.881819Z","bundle_sha256":"ba7a7587d7198ff963d5fc428b0eac6b8376c4c1e79641130d7e271c5e5180af"}}