{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:IPAOYDFLA6AOH4RDUUNIXNNF53","short_pith_number":"pith:IPAOYDFL","canonical_record":{"source":{"id":"1907.11646","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2019-07-26T16:03:42Z","cross_cats_sorted":[],"title_canon_sha256":"65a348c676b45d4fb53eded7d88ba2012fa975c9f4fefa2c583e45380bf5e8e9","abstract_canon_sha256":"5840fabc7506d65a990fa8e8e895c23d7e1500dce30dfa7962e4b43c66448ef0"},"schema_version":"1.0"},"canonical_sha256":"43c0ec0cab0780e3f223a51a8bb5a5eed78ff398a1ee32763f696b4f81c7de5b","source":{"kind":"arxiv","id":"1907.11646","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.11646","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"arxiv_version","alias_value":"1907.11646v1","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.11646","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"pith_short_12","alias_value":"IPAOYDFLA6AO","created_at":"2026-05-18T12:33:18Z"},{"alias_kind":"pith_short_16","alias_value":"IPAOYDFLA6AOH4RD","created_at":"2026-05-18T12:33:18Z"},{"alias_kind":"pith_short_8","alias_value":"IPAOYDFL","created_at":"2026-05-18T12:33:18Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:IPAOYDFLA6AOH4RDUUNIXNNF53","target":"record","payload":{"canonical_record":{"source":{"id":"1907.11646","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2019-07-26T16:03:42Z","cross_cats_sorted":[],"title_canon_sha256":"65a348c676b45d4fb53eded7d88ba2012fa975c9f4fefa2c583e45380bf5e8e9","abstract_canon_sha256":"5840fabc7506d65a990fa8e8e895c23d7e1500dce30dfa7962e4b43c66448ef0"},"schema_version":"1.0"},"canonical_sha256":"43c0ec0cab0780e3f223a51a8bb5a5eed78ff398a1ee32763f696b4f81c7de5b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:39:28.387557Z","signature_b64":"Z1IVgLyJbzsUb4Y3gRYS5UsF+gbCpcjAI/JSRgWwLogllEI2Na3O+jNPQoL8PTD16ZrpcUjY77D6wQ8YaVjSCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"43c0ec0cab0780e3f223a51a8bb5a5eed78ff398a1ee32763f696b4f81c7de5b","last_reissued_at":"2026-05-17T23:39:28.386724Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:39:28.386724Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1907.11646","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:39:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"doFsthTn/ZMKkJIEQvrFYt8T2s0h3avTssiiIBQG2FVv6yZsXHreXc/u1bRakQ33Kpq3vxUjFKEz2VdusZlUBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T05:30:04.903220Z"},"content_sha256":"10e969535be11d19ac5b44cfeaa03088d807f222546b6d33ad562ca158595eae","schema_version":"1.0","event_id":"sha256:10e969535be11d19ac5b44cfeaa03088d807f222546b6d33ad562ca158595eae"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:IPAOYDFLA6AOH4RDUUNIXNNF53","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Four-dimensional polarization-ring-switching for dispersion-managed optical fibre systems","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"eess.SP","authors_text":"Alex Alvarado, Bin Chen, Chigo Okonkwo, Hartmut Hafermann","submitted_at":"2019-07-26T16:03:42Z","abstract_excerpt":"The recently introduced 4D 64-ary polarisation-ring-switching format is investigated in dispersion-managed systems. Numerical simulations show a reach increase of $25\\%$ with respect to PM-8QAM. This gain is achieved from the nonlinear tolerance of the format and a 4D demapper using correlated noise assumptions."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.11646","kind":"arxiv","version":1},"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":"2026-05-17T23:39:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"EBxRgOIGPOV8FJ8PeLpWtznifXWhz3UN9d8q7xcQ42DwiQqcV70jd0Dz0/waIfLX31twn2kLrIC7E8VAf1HwBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T05:30:04.903989Z"},"content_sha256":"a0deac0b20966c7e5ce1af3a297452d977bd3bd6b87cb5e1291b045209f3b8b8","schema_version":"1.0","event_id":"sha256:a0deac0b20966c7e5ce1af3a297452d977bd3bd6b87cb5e1291b045209f3b8b8"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/bundle.json","state_url":"https://pith.science/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/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":"2026-05-30T05:30:04Z","links":{"resolver":"https://pith.science/pith/IPAOYDFLA6AOH4RDUUNIXNNF53","bundle":"https://pith.science/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/bundle.json","state":"https://pith.science/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IPAOYDFLA6AOH4RDUUNIXNNF53/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:IPAOYDFLA6AOH4RDUUNIXNNF53","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":"5840fabc7506d65a990fa8e8e895c23d7e1500dce30dfa7962e4b43c66448ef0","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2019-07-26T16:03:42Z","title_canon_sha256":"65a348c676b45d4fb53eded7d88ba2012fa975c9f4fefa2c583e45380bf5e8e9"},"schema_version":"1.0","source":{"id":"1907.11646","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.11646","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"arxiv_version","alias_value":"1907.11646v1","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.11646","created_at":"2026-05-17T23:39:28Z"},{"alias_kind":"pith_short_12","alias_value":"IPAOYDFLA6AO","created_at":"2026-05-18T12:33:18Z"},{"alias_kind":"pith_short_16","alias_value":"IPAOYDFLA6AOH4RD","created_at":"2026-05-18T12:33:18Z"},{"alias_kind":"pith_short_8","alias_value":"IPAOYDFL","created_at":"2026-05-18T12:33:18Z"}],"graph_snapshots":[{"event_id":"sha256:a0deac0b20966c7e5ce1af3a297452d977bd3bd6b87cb5e1291b045209f3b8b8","target":"graph","created_at":"2026-05-17T23:39:28Z","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 recently introduced 4D 64-ary polarisation-ring-switching format is investigated in dispersion-managed systems. Numerical simulations show a reach increase of $25\\%$ with respect to PM-8QAM. This gain is achieved from the nonlinear tolerance of the format and a 4D demapper using correlated noise assumptions.","authors_text":"Alex Alvarado, Bin Chen, Chigo Okonkwo, Hartmut Hafermann","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2019-07-26T16:03:42Z","title":"Four-dimensional polarization-ring-switching for dispersion-managed optical fibre systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.11646","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":"sha256:10e969535be11d19ac5b44cfeaa03088d807f222546b6d33ad562ca158595eae","target":"record","created_at":"2026-05-17T23:39:28Z","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":"5840fabc7506d65a990fa8e8e895c23d7e1500dce30dfa7962e4b43c66448ef0","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"eess.SP","submitted_at":"2019-07-26T16:03:42Z","title_canon_sha256":"65a348c676b45d4fb53eded7d88ba2012fa975c9f4fefa2c583e45380bf5e8e9"},"schema_version":"1.0","source":{"id":"1907.11646","kind":"arxiv","version":1}},"canonical_sha256":"43c0ec0cab0780e3f223a51a8bb5a5eed78ff398a1ee32763f696b4f81c7de5b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"43c0ec0cab0780e3f223a51a8bb5a5eed78ff398a1ee32763f696b4f81c7de5b","first_computed_at":"2026-05-17T23:39:28.386724Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:39:28.386724Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Z1IVgLyJbzsUb4Y3gRYS5UsF+gbCpcjAI/JSRgWwLogllEI2Na3O+jNPQoL8PTD16ZrpcUjY77D6wQ8YaVjSCg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:39:28.387557Z","signed_message":"canonical_sha256_bytes"},"source_id":"1907.11646","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:10e969535be11d19ac5b44cfeaa03088d807f222546b6d33ad562ca158595eae","sha256:a0deac0b20966c7e5ce1af3a297452d977bd3bd6b87cb5e1291b045209f3b8b8"],"state_sha256":"3dcea477e4173950945ffc8e1786eda7c716ff7a777e0fb2ac2b6ec78b931a11"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"NrKEq/xrJ7n2j0+91QDzLlh+iDn4EJSWBx0CTg36PrBsPpNWGud36gOfA7VhnQ64O37Y8n08W5wxmyHZlfjOAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T05:30:04.907561Z","bundle_sha256":"b0bd79027fcdf67bb7f4ecb13efcf0b44bcb429e843eea576f9fdfc461879509"}}