{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:QTDXU6M7ZX6JDGL4SF26TK2P4V","short_pith_number":"pith:QTDXU6M7","canonical_record":{"source":{"id":"1802.02236","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2018-02-06T21:54:21Z","cross_cats_sorted":[],"title_canon_sha256":"49bda9317520a27af519dacdd98a8b6e4e8e57562315d7fe316eaa972f371bf1","abstract_canon_sha256":"8ef284bff8c1b6db25fdf9cfa5a21d876fb11b73e9c348a5674c7b08d9138901"},"schema_version":"1.0"},"canonical_sha256":"84c77a799fcdfc91997c9175e9ab4fe5486f8b4b83ed17956200047e4d2adb68","source":{"kind":"arxiv","id":"1802.02236","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1802.02236","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"arxiv_version","alias_value":"1802.02236v2","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1802.02236","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"pith_short_12","alias_value":"QTDXU6M7ZX6J","created_at":"2026-05-18T12:32:46Z"},{"alias_kind":"pith_short_16","alias_value":"QTDXU6M7ZX6JDGL4","created_at":"2026-05-18T12:32:46Z"},{"alias_kind":"pith_short_8","alias_value":"QTDXU6M7","created_at":"2026-05-18T12:32:46Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:QTDXU6M7ZX6JDGL4SF26TK2P4V","target":"record","payload":{"canonical_record":{"source":{"id":"1802.02236","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2018-02-06T21:54:21Z","cross_cats_sorted":[],"title_canon_sha256":"49bda9317520a27af519dacdd98a8b6e4e8e57562315d7fe316eaa972f371bf1","abstract_canon_sha256":"8ef284bff8c1b6db25fdf9cfa5a21d876fb11b73e9c348a5674c7b08d9138901"},"schema_version":"1.0"},"canonical_sha256":"84c77a799fcdfc91997c9175e9ab4fe5486f8b4b83ed17956200047e4d2adb68","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:15:16.326397Z","signature_b64":"cB48zO/G/lYsYfcxqD7HQ+nB49KxpOYSAEUzvwGzeVTrrtwDioIqxzmbr2lqwwsrcQK0vypsEGYsMyMXe23gDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"84c77a799fcdfc91997c9175e9ab4fe5486f8b4b83ed17956200047e4d2adb68","last_reissued_at":"2026-05-18T00:15:16.325756Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:15:16.325756Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1802.02236","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:15:16Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JjTkrmCW91MKrhESi/zjIGpu1C6YT/rQpztERZ59DR+HgvEn0+2U+Vxt7Arv4F+ZGaR+g76c0XHScu6EvZwgCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T09:13:39.703467Z"},"content_sha256":"20aeb4c4cd2488a2a996d4a900676bdff0bf3bf6877681a3c830836e0f17f92d","schema_version":"1.0","event_id":"sha256:20aeb4c4cd2488a2a996d4a900676bdff0bf3bf6877681a3c830836e0f17f92d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:QTDXU6M7ZX6JDGL4SF26TK2P4V","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Designing scattering-free isotropic index profiles using phase-amplitude equations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.optics","authors_text":"Chris King, Simon Horsley, Thomas Philbin","submitted_at":"2018-02-06T21:54:21Z","abstract_excerpt":"The Helmholtz equation can be written as coupled equations for the amplitude and phase. By considering spatial phase distributions corresponding to reflectionless wave propagation in the plane and solving for the amplitude in terms of this phase, we designed two-dimensional graded-index media which do not scatter light. We give two illustrative examples, the first of which is a periodic grating for which diffraction is completely suppressed at a single frequency at normal incidence to the periodicity. The second example is a medium which behaves as a 'beam shifter' at a single frequency; actin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1802.02236","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:15:16Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1LzXIuwPmfCqN0xsETKipT+OnCy2dRcu/v3gEnWgZKhNlPNchdhxLJcA+gnRB9/Pr/U6zkwcirdE7XVyS7MzDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T09:13:39.703877Z"},"content_sha256":"b3dd737abf1cba0e8aa8308b2028d194743aa0be25d5f253c8cf545dc5b267d0","schema_version":"1.0","event_id":"sha256:b3dd737abf1cba0e8aa8308b2028d194743aa0be25d5f253c8cf545dc5b267d0"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/bundle.json","state_url":"https://pith.science/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-07T09:13:39Z","links":{"resolver":"https://pith.science/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V","bundle":"https://pith.science/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/bundle.json","state":"https://pith.science/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QTDXU6M7ZX6JDGL4SF26TK2P4V/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:QTDXU6M7ZX6JDGL4SF26TK2P4V","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":"8ef284bff8c1b6db25fdf9cfa5a21d876fb11b73e9c348a5674c7b08d9138901","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2018-02-06T21:54:21Z","title_canon_sha256":"49bda9317520a27af519dacdd98a8b6e4e8e57562315d7fe316eaa972f371bf1"},"schema_version":"1.0","source":{"id":"1802.02236","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1802.02236","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"arxiv_version","alias_value":"1802.02236v2","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1802.02236","created_at":"2026-05-18T00:15:16Z"},{"alias_kind":"pith_short_12","alias_value":"QTDXU6M7ZX6J","created_at":"2026-05-18T12:32:46Z"},{"alias_kind":"pith_short_16","alias_value":"QTDXU6M7ZX6JDGL4","created_at":"2026-05-18T12:32:46Z"},{"alias_kind":"pith_short_8","alias_value":"QTDXU6M7","created_at":"2026-05-18T12:32:46Z"}],"graph_snapshots":[{"event_id":"sha256:b3dd737abf1cba0e8aa8308b2028d194743aa0be25d5f253c8cf545dc5b267d0","target":"graph","created_at":"2026-05-18T00:15:16Z","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"},"paper":{"abstract_excerpt":"The Helmholtz equation can be written as coupled equations for the amplitude and phase. By considering spatial phase distributions corresponding to reflectionless wave propagation in the plane and solving for the amplitude in terms of this phase, we designed two-dimensional graded-index media which do not scatter light. We give two illustrative examples, the first of which is a periodic grating for which diffraction is completely suppressed at a single frequency at normal incidence to the periodicity. The second example is a medium which behaves as a 'beam shifter' at a single frequency; actin","authors_text":"Chris King, Simon Horsley, Thomas Philbin","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2018-02-06T21:54:21Z","title":"Designing scattering-free isotropic index profiles using phase-amplitude equations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1802.02236","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":"sha256:20aeb4c4cd2488a2a996d4a900676bdff0bf3bf6877681a3c830836e0f17f92d","target":"record","created_at":"2026-05-18T00:15:16Z","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":"8ef284bff8c1b6db25fdf9cfa5a21d876fb11b73e9c348a5674c7b08d9138901","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2018-02-06T21:54:21Z","title_canon_sha256":"49bda9317520a27af519dacdd98a8b6e4e8e57562315d7fe316eaa972f371bf1"},"schema_version":"1.0","source":{"id":"1802.02236","kind":"arxiv","version":2}},"canonical_sha256":"84c77a799fcdfc91997c9175e9ab4fe5486f8b4b83ed17956200047e4d2adb68","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"84c77a799fcdfc91997c9175e9ab4fe5486f8b4b83ed17956200047e4d2adb68","first_computed_at":"2026-05-18T00:15:16.325756Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:15:16.325756Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"cB48zO/G/lYsYfcxqD7HQ+nB49KxpOYSAEUzvwGzeVTrrtwDioIqxzmbr2lqwwsrcQK0vypsEGYsMyMXe23gDw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:15:16.326397Z","signed_message":"canonical_sha256_bytes"},"source_id":"1802.02236","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:20aeb4c4cd2488a2a996d4a900676bdff0bf3bf6877681a3c830836e0f17f92d","sha256:b3dd737abf1cba0e8aa8308b2028d194743aa0be25d5f253c8cf545dc5b267d0"],"state_sha256":"29d70b8b83fa109bdb3dfea08b254eba525c0584df1a49f9836f31fed946351c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"p1tIqwbN7Y8Ygp01dm8E+IMcy2senDsprZGRO+/8hcHNOuB9kSmepx9z0Z6KejBfjKeIY4BQgeXtWuu8VnvlDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-07T09:13:39.706137Z","bundle_sha256":"242ad1f4b519b28f348440381772fdfc67bef8919bcfd589342e63f109bb418f"}}