{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:5CMPFUHFRA7G5JG25PWH2R75TP","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":"1a2ec8398238212f145c0494b7c9e9fd950caf477a5ca8ea7c9ebeedc4e76ee2","cross_cats_sorted":["gr-qc"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2020-02-10T17:34:51Z","title_canon_sha256":"774891f368ab875f3866a4dfc6da0a2050f631c543d506581830153e9ef7a71e"},"schema_version":"1.0","source":{"id":"2002.04216","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2002.04216","created_at":"2026-07-05T02:23:04Z"},{"alias_kind":"arxiv_version","alias_value":"2002.04216v2","created_at":"2026-07-05T02:23:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2002.04216","created_at":"2026-07-05T02:23:04Z"},{"alias_kind":"pith_short_12","alias_value":"5CMPFUHFRA7G","created_at":"2026-07-05T02:23:04Z"},{"alias_kind":"pith_short_16","alias_value":"5CMPFUHFRA7G5JG2","created_at":"2026-07-05T02:23:04Z"},{"alias_kind":"pith_short_8","alias_value":"5CMPFUHF","created_at":"2026-07-05T02:23:04Z"}],"graph_snapshots":[{"event_id":"sha256:1056bc126e9b32d1d2b1f720d069be99fa9b4adef3659ff3adab54205384d947","target":"graph","created_at":"2026-07-05T02:23:04Z","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/2002.04216/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Hawking radiation is unlikely to be measured from a real black-hole, but can be tested in laboratory analogues. It was predicted as a consequence of quantum mechanics and general relativity, but turned out to be more universal. A refractive index perturbation produce an optical analogue of the black-hole horizon and Hawking radiation that is made of light. We discuss the central and recent experiments of the optical analogue, using hands-on physics. We stress the roles of classical fields, negative frequencies, 'regular optics' and dispersion. Opportunities and challenges ahead are shortly dis","authors_text":"Yuval Rosenberg","cross_cats":["gr-qc"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2020-02-10T17:34:51Z","title":"Optical analogues of black-hole horizons"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2002.04216","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:f090ec352becf4e92f95035f60976bbffa06b8c119e1fab129b10abf284d57b7","target":"record","created_at":"2026-07-05T02:23:04Z","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":"1a2ec8398238212f145c0494b7c9e9fd950caf477a5ca8ea7c9ebeedc4e76ee2","cross_cats_sorted":["gr-qc"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2020-02-10T17:34:51Z","title_canon_sha256":"774891f368ab875f3866a4dfc6da0a2050f631c543d506581830153e9ef7a71e"},"schema_version":"1.0","source":{"id":"2002.04216","kind":"arxiv","version":2}},"canonical_sha256":"e898f2d0e5883e6ea4daebec7d47fd9bd88762fd5d3594677bd026b7fd334b3f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e898f2d0e5883e6ea4daebec7d47fd9bd88762fd5d3594677bd026b7fd334b3f","first_computed_at":"2026-07-05T02:23:04.843130Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:23:04.843130Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"EROOERTYnkwJ2bz0ljZwnS/whddroxjia02BELE9AwzZgoHTQdNxTmltYwlVmtswrvJT7SrinoinrEDOJMMXDg==","signature_status":"signed_v1","signed_at":"2026-07-05T02:23:04.843570Z","signed_message":"canonical_sha256_bytes"},"source_id":"2002.04216","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f090ec352becf4e92f95035f60976bbffa06b8c119e1fab129b10abf284d57b7","sha256:1056bc126e9b32d1d2b1f720d069be99fa9b4adef3659ff3adab54205384d947"],"state_sha256":"c744e4899d9380b96632fc746b12665264f97e462930127e09dd6d7056546d25"}