{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2000:LVH2AYS7LLF5BL5FQPT56XMQMU","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":"9ba16c93856ec850d17f0f74dc52e059dfd9a5f89465b9d996fc6324c5e13a43","cross_cats_sorted":[],"license":"","primary_cat":"physics.optics","submitted_at":"2000-03-23T20:11:24Z","title_canon_sha256":"26821009275f3eceba1a984ed50a183d7b806d54ea6d58800d689dd2abfe49d2"},"schema_version":"1.0","source":{"id":"physics/0003058","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"physics/0003058","created_at":"2026-07-04T14:43:13Z"},{"alias_kind":"arxiv_version","alias_value":"physics/0003058v1","created_at":"2026-07-04T14:43:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.physics/0003058","created_at":"2026-07-04T14:43:13Z"},{"alias_kind":"pith_short_12","alias_value":"LVH2AYS7LLF5","created_at":"2026-07-04T14:43:13Z"},{"alias_kind":"pith_short_16","alias_value":"LVH2AYS7LLF5BL5F","created_at":"2026-07-04T14:43:13Z"},{"alias_kind":"pith_short_8","alias_value":"LVH2AYS7","created_at":"2026-07-04T14:43:13Z"}],"graph_snapshots":[{"event_id":"sha256:9f72bfdfa22a4d46bba6d5a873f224e0c263ad9f5c9164fc7682e90a1529ea3e","target":"graph","created_at":"2026-07-04T14:43:13Z","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/physics/0003058/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We show that a time-reversed formulation of Huygens-Kirchhoff diffraction can be used to deduce the transverse and longitudinal fields of a Gaussian laser beam, starting from a simple assumption of a Gaussian beam profile in the far field. An attempt to apply this technique to the far fields of a Hertzian dipole shows how the laws of diffraction do not permit a wave to be focused to a volume smaller than a cubic wavelength in a charge-free region.","authors_text":"Kirk T. McDonald, Max S. Zolotorev","cross_cats":[],"headline":"","license":"","primary_cat":"physics.optics","submitted_at":"2000-03-23T20:11:24Z","title":"Time-Reversed Diffraction"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"physics/0003058","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:caf6ce4d7944a01e4785a84f1c4d2d2d950f7a11c6f9014da7c817b580e7ceb9","target":"record","created_at":"2026-07-04T14:43:13Z","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":"9ba16c93856ec850d17f0f74dc52e059dfd9a5f89465b9d996fc6324c5e13a43","cross_cats_sorted":[],"license":"","primary_cat":"physics.optics","submitted_at":"2000-03-23T20:11:24Z","title_canon_sha256":"26821009275f3eceba1a984ed50a183d7b806d54ea6d58800d689dd2abfe49d2"},"schema_version":"1.0","source":{"id":"physics/0003058","kind":"arxiv","version":1}},"canonical_sha256":"5d4fa0625f5acbd0afa583e7df5d90651399e0608d5533a587daf6793978b4b2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5d4fa0625f5acbd0afa583e7df5d90651399e0608d5533a587daf6793978b4b2","first_computed_at":"2026-07-04T14:43:13.935273Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T14:43:13.935273Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"95Dg6mp6jwKwZA/2oTCJMDzezoKrUDVFE6NsR3SjmragBrYACa+oSs/hIKRBouGYSqTZed0zkaFd1O1VcS0oBg==","signature_status":"signed_v1","signed_at":"2026-07-04T14:43:13.935665Z","signed_message":"canonical_sha256_bytes"},"source_id":"physics/0003058","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:caf6ce4d7944a01e4785a84f1c4d2d2d950f7a11c6f9014da7c817b580e7ceb9","sha256:9f72bfdfa22a4d46bba6d5a873f224e0c263ad9f5c9164fc7682e90a1529ea3e"],"state_sha256":"ab76799bf6be78a4a3849db04f3d28720d5d3197354931bd288bd8c30c570421"}