{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:QBZJ5XDCVEWMTINYZLXH646UNP","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":"30426df60f85e9b93b51d98f29147661527471d6501c8c6fcf69e7fd2f1cc108","cross_cats_sorted":["astro-ph.HE","hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2020-07-20T18:00:00Z","title_canon_sha256":"2c765c71742b3204d2ae69e36aa71b3264f352a85f365e5c8c717d2d764482a5"},"schema_version":"1.0","source":{"id":"2007.10336","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2007.10336","created_at":"2026-07-05T01:57:52Z"},{"alias_kind":"arxiv_version","alias_value":"2007.10336v1","created_at":"2026-07-05T01:57:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2007.10336","created_at":"2026-07-05T01:57:52Z"},{"alias_kind":"pith_short_12","alias_value":"QBZJ5XDCVEWM","created_at":"2026-07-05T01:57:52Z"},{"alias_kind":"pith_short_16","alias_value":"QBZJ5XDCVEWMTINY","created_at":"2026-07-05T01:57:52Z"},{"alias_kind":"pith_short_8","alias_value":"QBZJ5XDC","created_at":"2026-07-05T01:57:52Z"}],"graph_snapshots":[{"event_id":"sha256:438fc6506f86a143070e56436c414eb33b518dc906a387873935c77d36e65014","target":"graph","created_at":"2026-07-05T01:57:52Z","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/2007.10336/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Motivated by the prospect of measuring a black hole photon ring, in previous work we explored the interferometric signature produced by a bright, narrow curve in the sky. Interferometric observations of such a curve measure its \"projected position function\" $\\mathbf{r}\\cdot\\hat{\\mathbf{n}}$, where $\\mathbf{r}$ parameterizes the curve and $\\hat{\\mathbf{n}}$ denotes its unit normal vector. In this paper, we show by explicit construction that a curve can be fully reconstructed from its projected position, completing the argument that space interferometry can in principle determine the detailed ph","authors_text":"Alexandru Lupsasca, Samuel E. Gralla","cross_cats":["astro-ph.HE","hep-th"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2020-07-20T18:00:00Z","title":"On the Observable Shape of Black Hole Photon Rings"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2007.10336","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:c509caf2fa7da6e660b767f02521f30832b3e69dec9833b695dd0a15b8ff8f80","target":"record","created_at":"2026-07-05T01:57:52Z","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":"30426df60f85e9b93b51d98f29147661527471d6501c8c6fcf69e7fd2f1cc108","cross_cats_sorted":["astro-ph.HE","hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2020-07-20T18:00:00Z","title_canon_sha256":"2c765c71742b3204d2ae69e36aa71b3264f352a85f365e5c8c717d2d764482a5"},"schema_version":"1.0","source":{"id":"2007.10336","kind":"arxiv","version":1}},"canonical_sha256":"80729edc62a92cc9a1b8caee7f73d46bfef00a223c98b35d5a38ddd24359de54","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"80729edc62a92cc9a1b8caee7f73d46bfef00a223c98b35d5a38ddd24359de54","first_computed_at":"2026-07-05T01:57:52.796784Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:57:52.796784Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"QWxPd22qKtT6fCSKf32EjgPJAL4ExuKNIOl9PgO91TpuTkKwL2CGISWS/d9pAvT8DB8aokAdwJY1Nkxbg20DBQ==","signature_status":"signed_v1","signed_at":"2026-07-05T01:57:52.797237Z","signed_message":"canonical_sha256_bytes"},"source_id":"2007.10336","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c509caf2fa7da6e660b767f02521f30832b3e69dec9833b695dd0a15b8ff8f80","sha256:438fc6506f86a143070e56436c414eb33b518dc906a387873935c77d36e65014"],"state_sha256":"3de64390a14d749001d1c1857a3d7ca237c84a165513b652a35a461df1823ed7"}