{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:YLZZEJWUF2X24RB7WTZXRVL65P","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":"63941a82c28bf84b2154f806e77f5913d1cd6dd812d452f6a4a3275531afecc0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-05-03T12:18:03Z","title_canon_sha256":"29e2b875d6463e6145fe8f772a38574e6029717edfb48354cb0262c56f133432"},"schema_version":"1.0","source":{"id":"1305.0681","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1305.0681","created_at":"2026-05-18T03:10:03Z"},{"alias_kind":"arxiv_version","alias_value":"1305.0681v3","created_at":"2026-05-18T03:10:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1305.0681","created_at":"2026-05-18T03:10:03Z"},{"alias_kind":"pith_short_12","alias_value":"YLZZEJWUF2X2","created_at":"2026-05-18T12:28:06Z"},{"alias_kind":"pith_short_16","alias_value":"YLZZEJWUF2X24RB7","created_at":"2026-05-18T12:28:06Z"},{"alias_kind":"pith_short_8","alias_value":"YLZZEJWU","created_at":"2026-05-18T12:28:06Z"}],"graph_snapshots":[{"event_id":"sha256:8d1f03e70df0a3032efffcda5039032906b05465d692c5b8e1c10978416d0fab","target":"graph","created_at":"2026-05-18T03:10:03Z","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":"A density matrix {\\rho}(t) yields probabilistic information about the outcome of measurements on a quantum system. We introduce here the past quantum state, which, at time T, accounts for the state of a quantum system at earlier times t < T. The past quantum state {\\Xi}(t) is composed of two objects, {\\rho}(t) and E(t), conditioned on the dynamics and the probing of the system until t and in the time interval [t, T], respectively. The past quantum state is characterized by its ability to make better predictions for the unknown outcome of projective and weak value measurements at t than the con","authors_text":"Brian Julsgaard, Klaus M{\\o}lmer, S{\\o}ren Gammelmark","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-05-03T12:18:03Z","title":"Past quantum states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1305.0681","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":"sha256:22698d8eeb0219bd7206c5f8b5740f5166631eaf2311921bbf0887e77a416737","target":"record","created_at":"2026-05-18T03:10:03Z","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":"63941a82c28bf84b2154f806e77f5913d1cd6dd812d452f6a4a3275531afecc0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-05-03T12:18:03Z","title_canon_sha256":"29e2b875d6463e6145fe8f772a38574e6029717edfb48354cb0262c56f133432"},"schema_version":"1.0","source":{"id":"1305.0681","kind":"arxiv","version":3}},"canonical_sha256":"c2f39226d42eafae443fb4f378d57eebca7fd462852241b7f14b790bf0aca534","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c2f39226d42eafae443fb4f378d57eebca7fd462852241b7f14b790bf0aca534","first_computed_at":"2026-05-18T03:10:03.389196Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:10:03.389196Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"L3STwSbgH7mqQHV5pPq6muw5f/3y+Sk0/ShAtL2qBhS/P3KF7LEi45ECJueSpWKv/b/9WGEnvvAkM80KuKu/CQ==","signature_status":"signed_v1","signed_at":"2026-05-18T03:10:03.389752Z","signed_message":"canonical_sha256_bytes"},"source_id":"1305.0681","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:22698d8eeb0219bd7206c5f8b5740f5166631eaf2311921bbf0887e77a416737","sha256:8d1f03e70df0a3032efffcda5039032906b05465d692c5b8e1c10978416d0fab"],"state_sha256":"b9e6b93295139da1b8b0343cc073672a95677fc091d8ae5e93e579fa28c6a5c0"}