{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2019:K3GSY6Z6RA23PXEOTPIK5FI3DV","short_pith_number":"pith:K3GSY6Z6","schema_version":"1.0","canonical_sha256":"56cd2c7b3e8835b7dc8e9bd0ae951b1d51de1261a4c6ea0e6aedc55ee581d991","source":{"kind":"arxiv","id":"1908.11794","version":1},"attestation_state":"computed","paper":{"title":"Testing the Schwarzschild metric in a strong field region with the Event Horizon Telescope","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"gr-qc","authors_text":"S. X. Tian, Zong-Hong Zhu","submitted_at":"2019-08-30T15:36:22Z","abstract_excerpt":"Testing gravity theory in the strong field region becomes a reality due to the observations of gravitational waves and black hole shadows. In this paper, we discuss how to constrain the possible deviations of the classical general relativity with the image of M87* observed by the Event Horizon Telescope. More precisely, we want to know where is the event horizon for a non-rotating black hole. General relativity predicts the horizon is located at the Schwarzschild radius $r_\\textrm{s}$, while other gravity theories may give different predictions. We propose a parameterized Schwarzschild metric "},"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":"1908.11794","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2019-08-30T15:36:22Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"14b776fcfdeff84f18e268dc18621e429f25d1663517bb1f42fc3066310d7c56","abstract_canon_sha256":"d0f2fb9b8aaf99fd61f17f45b99e6e4bf9fba316fd636db8d5e8b60e4d0a95a2"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:03:01.105712Z","signature_b64":"yL479sRUwCb7MRfDDJkqJW/5VhsuhUzfIvl2CzjGUtAWRuFx4iIhyMvsFEbSznKpB9EuCqxVni2ZeEFm0r9iBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"56cd2c7b3e8835b7dc8e9bd0ae951b1d51de1261a4c6ea0e6aedc55ee581d991","last_reissued_at":"2026-07-05T00:03:01.105283Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:03:01.105283Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Testing the Schwarzschild metric in a strong field region with the Event Horizon Telescope","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"gr-qc","authors_text":"S. X. Tian, Zong-Hong Zhu","submitted_at":"2019-08-30T15:36:22Z","abstract_excerpt":"Testing gravity theory in the strong field region becomes a reality due to the observations of gravitational waves and black hole shadows. In this paper, we discuss how to constrain the possible deviations of the classical general relativity with the image of M87* observed by the Event Horizon Telescope. More precisely, we want to know where is the event horizon for a non-rotating black hole. General relativity predicts the horizon is located at the Schwarzschild radius $r_\\textrm{s}$, while other gravity theories may give different predictions. We propose a parameterized Schwarzschild metric "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1908.11794","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/1908.11794/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":"1908.11794","created_at":"2026-07-05T00:03:01.105334+00:00"},{"alias_kind":"arxiv_version","alias_value":"1908.11794v1","created_at":"2026-07-05T00:03:01.105334+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1908.11794","created_at":"2026-07-05T00:03:01.105334+00:00"},{"alias_kind":"pith_short_12","alias_value":"K3GSY6Z6RA23","created_at":"2026-07-05T00:03:01.105334+00:00"},{"alias_kind":"pith_short_16","alias_value":"K3GSY6Z6RA23PXEO","created_at":"2026-07-05T00:03:01.105334+00:00"},{"alias_kind":"pith_short_8","alias_value":"K3GSY6Z6","created_at":"2026-07-05T00:03:01.105334+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":1,"internal_anchor_count":0,"sample":[{"citing_arxiv_id":"2604.09046","citing_title":"Relative Magnification Factor of Point Sources on Accretion Disks","ref_index":67,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV","json":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV.json","graph_json":"https://pith.science/api/pith-number/K3GSY6Z6RA23PXEOTPIK5FI3DV/graph.json","events_json":"https://pith.science/api/pith-number/K3GSY6Z6RA23PXEOTPIK5FI3DV/events.json","paper":"https://pith.science/paper/K3GSY6Z6"},"agent_actions":{"view_html":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV","download_json":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV.json","view_paper":"https://pith.science/paper/K3GSY6Z6","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1908.11794&json=true","fetch_graph":"https://pith.science/api/pith-number/K3GSY6Z6RA23PXEOTPIK5FI3DV/graph.json","fetch_events":"https://pith.science/api/pith-number/K3GSY6Z6RA23PXEOTPIK5FI3DV/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV/action/timestamp_anchor","attest_storage":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV/action/storage_attestation","attest_author":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV/action/author_attestation","sign_citation":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV/action/citation_signature","submit_replication":"https://pith.science/pith/K3GSY6Z6RA23PXEOTPIK5FI3DV/action/replication_record"}},"created_at":"2026-07-05T00:03:01.105334+00:00","updated_at":"2026-07-05T00:03:01.105334+00:00"}