{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2009:Q2KSTQ5YZEAYYFONRZH7V53J5N","short_pith_number":"pith:Q2KSTQ5Y","schema_version":"1.0","canonical_sha256":"869529c3b8c9018c15cd8e4ffaf769eb41ddee16ef278da80c23855c28b3de57","source":{"kind":"arxiv","id":"0901.4587","version":2},"attestation_state":"computed","paper":{"title":"On the intensity interferometry and the second-order correlation function $g^{(2)}$ in astrophysics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"C. Foellmi","submitted_at":"2009-01-28T23:59:12Z","abstract_excerpt":"Most observational techniques in astronomy can be understood as exploiting the various forms of the first-order correlation function g^(1). As however demonstrated by the Narrabri Stellar Intensity Interferometer back in the 1960's by Hanbury Brown & Twiss, and which is the first experiment to measure the second-order correlation function g^(2), light can carry more information than simply its intensity, spectrum and polarization. Since this experiment, theoretical and laboratory studies of non-classical properties of light have become a very active field of research, namely quantum optics. De"},"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":"0901.4587","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2009-01-28T23:59:12Z","cross_cats_sorted":[],"title_canon_sha256":"85b4c9e73d9772f75d367615d88bf0aa2bca65ff0af4ff2a02a6c560f825344a","abstract_canon_sha256":"62df9c83b2556588a91c605cd81597f0cb52511615c51ffa7e6bc2db40455477"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:14:55.334535Z","signature_b64":"aa5so8PmHcnhdPyXTCCGv67+0ehlvMoUAG4zBNl58MUOjxApCfr/k8xcenGHmgrpOGyV/LiIosIYmIuZz5xbCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"869529c3b8c9018c15cd8e4ffaf769eb41ddee16ef278da80c23855c28b3de57","last_reissued_at":"2026-05-18T02:14:55.333897Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:14:55.333897Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"On the intensity interferometry and the second-order correlation function $g^{(2)}$ in astrophysics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"C. Foellmi","submitted_at":"2009-01-28T23:59:12Z","abstract_excerpt":"Most observational techniques in astronomy can be understood as exploiting the various forms of the first-order correlation function g^(1). As however demonstrated by the Narrabri Stellar Intensity Interferometer back in the 1960's by Hanbury Brown & Twiss, and which is the first experiment to measure the second-order correlation function g^(2), light can carry more information than simply its intensity, spectrum and polarization. Since this experiment, theoretical and laboratory studies of non-classical properties of light have become a very active field of research, namely quantum optics. De"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0901.4587","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":""},"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":"0901.4587","created_at":"2026-05-18T02:14:55.334010+00:00"},{"alias_kind":"arxiv_version","alias_value":"0901.4587v2","created_at":"2026-05-18T02:14:55.334010+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0901.4587","created_at":"2026-05-18T02:14:55.334010+00:00"},{"alias_kind":"pith_short_12","alias_value":"Q2KSTQ5YZEAY","created_at":"2026-05-18T12:26:01.383474+00:00"},{"alias_kind":"pith_short_16","alias_value":"Q2KSTQ5YZEAYYFON","created_at":"2026-05-18T12:26:01.383474+00:00"},{"alias_kind":"pith_short_8","alias_value":"Q2KSTQ5Y","created_at":"2026-05-18T12:26:01.383474+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N","json":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N.json","graph_json":"https://pith.science/api/pith-number/Q2KSTQ5YZEAYYFONRZH7V53J5N/graph.json","events_json":"https://pith.science/api/pith-number/Q2KSTQ5YZEAYYFONRZH7V53J5N/events.json","paper":"https://pith.science/paper/Q2KSTQ5Y"},"agent_actions":{"view_html":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N","download_json":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N.json","view_paper":"https://pith.science/paper/Q2KSTQ5Y","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0901.4587&json=true","fetch_graph":"https://pith.science/api/pith-number/Q2KSTQ5YZEAYYFONRZH7V53J5N/graph.json","fetch_events":"https://pith.science/api/pith-number/Q2KSTQ5YZEAYYFONRZH7V53J5N/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N/action/timestamp_anchor","attest_storage":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N/action/storage_attestation","attest_author":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N/action/author_attestation","sign_citation":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N/action/citation_signature","submit_replication":"https://pith.science/pith/Q2KSTQ5YZEAYYFONRZH7V53J5N/action/replication_record"}},"created_at":"2026-05-18T02:14:55.334010+00:00","updated_at":"2026-05-18T02:14:55.334010+00:00"}