{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2020:K4ZGY6TEVLKLNA5RVHODTTRA3L","short_pith_number":"pith:K4ZGY6TE","schema_version":"1.0","canonical_sha256":"57326c7a64aad4b683b1a9dc39ce20dace262150cae7c9fca3ff32caa5fb7150","source":{"kind":"arxiv","id":"2001.02986","version":2},"attestation_state":"computed","paper":{"title":"Concerns regarding the use of black hole shadows as standard rulers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","astro-ph.HE"],"primary_cat":"gr-qc","authors_text":"Cosimo Bambi, Luca Visinelli, Sunny Vagnozzi","submitted_at":"2020-01-09T13:59:49Z","abstract_excerpt":"Recently, Tsupko et al. have put forward the very interesting proposal to use the shadows of high-redshift supermassive black holes (SMBHs) as standard rulers. This would in principle allow us to probe the expansion history within a redshift range which would otherwise be challenging to access. In this note, we critically examine this proposal, and identify a number of important issues which had been previously overlooked. These include difficulties in obtaining reliable SMBH mass estimates and reaching the required angular resolution, and an insufficient knowledge of the accretion dynamics of"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"2001.02986","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2020-01-09T13:59:49Z","cross_cats_sorted":["astro-ph.CO","astro-ph.HE"],"title_canon_sha256":"13ec401bc9ab34601a40cb2ee2155cbf31abc95485598e49f61cbb3df541959b","abstract_canon_sha256":"2b9132fd988b22abf44539f92fb5773ed39f585bfbe806818e41ed72a354bc32"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:52:17.615899Z","signature_b64":"pK1qE12OUmV14e+FSGmFip214cm+FVwzTtjDDahlXbNnFPhS/uy85B7l2nZpnUyx/YWGzeXatvqcbfgZMKjNCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"57326c7a64aad4b683b1a9dc39ce20dace262150cae7c9fca3ff32caa5fb7150","last_reissued_at":"2026-07-05T00:52:17.615421Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:52:17.615421Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Concerns regarding the use of black hole shadows as standard rulers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","astro-ph.HE"],"primary_cat":"gr-qc","authors_text":"Cosimo Bambi, Luca Visinelli, Sunny Vagnozzi","submitted_at":"2020-01-09T13:59:49Z","abstract_excerpt":"Recently, Tsupko et al. have put forward the very interesting proposal to use the shadows of high-redshift supermassive black holes (SMBHs) as standard rulers. This would in principle allow us to probe the expansion history within a redshift range which would otherwise be challenging to access. In this note, we critically examine this proposal, and identify a number of important issues which had been previously overlooked. These include difficulties in obtaining reliable SMBH mass estimates and reaching the required angular resolution, and an insufficient knowledge of the accretion dynamics of"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2001.02986","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/2001.02986/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"2001.02986","created_at":"2026-07-05T00:52:17.615481+00:00"},{"alias_kind":"arxiv_version","alias_value":"2001.02986v2","created_at":"2026-07-05T00:52:17.615481+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2001.02986","created_at":"2026-07-05T00:52:17.615481+00:00"},{"alias_kind":"pith_short_12","alias_value":"K4ZGY6TEVLKL","created_at":"2026-07-05T00:52:17.615481+00:00"},{"alias_kind":"pith_short_16","alias_value":"K4ZGY6TEVLKLNA5R","created_at":"2026-07-05T00:52:17.615481+00:00"},{"alias_kind":"pith_short_8","alias_value":"K4ZGY6TE","created_at":"2026-07-05T00:52:17.615481+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":3,"internal_anchor_count":1,"sample":[{"citing_arxiv_id":"2607.07752","citing_title":"Observational Limits on Einasto Dark Matter Parameters from Event Horizon Telescope Images of Sgr A$^{*}$ and M87$^{*}$","ref_index":33,"is_internal_anchor":true},{"citing_arxiv_id":"2606.06355","citing_title":"$\\tt BlackHawk$ $\\tt v3.0$: Hawking Radiation from Regular Black Holes","ref_index":38,"is_internal_anchor":false},{"citing_arxiv_id":"2602.16237","citing_title":"Rotating Black Holes with Primary Scalar Hair: Shadow Signatures in Beyond Horndeski Gravity","ref_index":104,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L","json":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L.json","graph_json":"https://pith.science/api/pith-number/K4ZGY6TEVLKLNA5RVHODTTRA3L/graph.json","events_json":"https://pith.science/api/pith-number/K4ZGY6TEVLKLNA5RVHODTTRA3L/events.json","paper":"https://pith.science/paper/K4ZGY6TE"},"agent_actions":{"view_html":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L","download_json":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L.json","view_paper":"https://pith.science/paper/K4ZGY6TE","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2001.02986&json=true","fetch_graph":"https://pith.science/api/pith-number/K4ZGY6TEVLKLNA5RVHODTTRA3L/graph.json","fetch_events":"https://pith.science/api/pith-number/K4ZGY6TEVLKLNA5RVHODTTRA3L/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L/action/timestamp_anchor","attest_storage":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L/action/storage_attestation","attest_author":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L/action/author_attestation","sign_citation":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L/action/citation_signature","submit_replication":"https://pith.science/pith/K4ZGY6TEVLKLNA5RVHODTTRA3L/action/replication_record"}},"created_at":"2026-07-05T00:52:17.615481+00:00","updated_at":"2026-07-05T00:52:17.615481+00:00"}