{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:CKG2GCSFGL562HMJXE33QYPUUJ","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":"4ebd71ac47342e819974cdcb7ca5588243af94fa0d694b43ebd349d70453bba6","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-01-21T17:01:06Z","title_canon_sha256":"8c5e01a9e149e75c11feb761a85a687c4274030a7bde8223ad078a4372b2c129"},"schema_version":"1.0","source":{"id":"1301.4927","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1301.4927","created_at":"2026-05-18T03:04:06Z"},{"alias_kind":"arxiv_version","alias_value":"1301.4927v3","created_at":"2026-05-18T03:04:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1301.4927","created_at":"2026-05-18T03:04:06Z"},{"alias_kind":"pith_short_12","alias_value":"CKG2GCSFGL56","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_16","alias_value":"CKG2GCSFGL562HMJ","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_8","alias_value":"CKG2GCSF","created_at":"2026-05-18T12:27:40Z"}],"graph_snapshots":[{"event_id":"sha256:ed1db24175d6ee3a202b93de8b1f7c9eb6053320ba2703df7d624626c93a898a","target":"graph","created_at":"2026-05-18T03:04:06Z","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":"We exhibit a possible road towards a strong converse for the quantum capacity of degradable channels. In particular, we show that all degradable channels obey what we call a \"pretty strong\" converse: When the code rate increases above the quantum capacity, the fidelity makes a discontinuous jump from 1 to at most 0.707, asymptotically. A similar result can be shown for the private (classical) capacity. Furthermore, we can show that if the strong converse holds for symmetric channels (which have quantum capacity zero), then degradable channels obey the strong converse: The above-mentioned asymp","authors_text":"Andreas Winter, Ciara Morgan","cross_cats":["cs.IT","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-01-21T17:01:06Z","title":"\"Pretty strong\" converse for the quantum capacity of degradable channels"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1301.4927","kind":"arxiv","version":3},"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":"sha256:13114543f785073d31ed7ebdf69aa66e62a064a8530a66124f1fb36955edcc0f","target":"record","created_at":"2026-05-18T03:04:06Z","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":"4ebd71ac47342e819974cdcb7ca5588243af94fa0d694b43ebd349d70453bba6","cross_cats_sorted":["cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-01-21T17:01:06Z","title_canon_sha256":"8c5e01a9e149e75c11feb761a85a687c4274030a7bde8223ad078a4372b2c129"},"schema_version":"1.0","source":{"id":"1301.4927","kind":"arxiv","version":3}},"canonical_sha256":"128da30a4532fbed1d89b937b861f4a27e88d816f0cc846138d415ad5b402997","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"128da30a4532fbed1d89b937b861f4a27e88d816f0cc846138d415ad5b402997","first_computed_at":"2026-05-18T03:04:06.639017Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:04:06.639017Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"3V0REZwoGsRupftMAl8CDBxsZKOFl9Rcd3UCk9xz7C/De/Mh1AxxYsMd5allWVp0L6cHYpCozTtXaYAgv5ZuAw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:04:06.639459Z","signed_message":"canonical_sha256_bytes"},"source_id":"1301.4927","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:13114543f785073d31ed7ebdf69aa66e62a064a8530a66124f1fb36955edcc0f","sha256:ed1db24175d6ee3a202b93de8b1f7c9eb6053320ba2703df7d624626c93a898a"],"state_sha256":"cf1afe9f065f837fe70cc9dfa23142e274c71e21cde2136c47a98be1ecb842c1"}