{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2008:B2LVRQTZEEZXKWCFDEWXDNQFTU","short_pith_number":"pith:B2LVRQTZ","canonical_record":{"source":{"id":"0812.1474","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2008-12-08T11:58:18Z","cross_cats_sorted":[],"title_canon_sha256":"eb76aa48efa4e79902a2ad492affa3aada80dbe3b6d047711a6a70968133bd94","abstract_canon_sha256":"2d0ce4cc17ff1d0e7dcf4bdaba333e19ecebf446c316b5318c10e5283baa6fa1"},"schema_version":"1.0"},"canonical_sha256":"0e9758c2792133755845192d71b6059d0ab51479d5b1440776a8b69a3865e979","source":{"kind":"arxiv","id":"0812.1474","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0812.1474","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"arxiv_version","alias_value":"0812.1474v2","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0812.1474","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"pith_short_12","alias_value":"B2LVRQTZEEZX","created_at":"2026-05-18T12:25:56Z"},{"alias_kind":"pith_short_16","alias_value":"B2LVRQTZEEZXKWCF","created_at":"2026-05-18T12:25:56Z"},{"alias_kind":"pith_short_8","alias_value":"B2LVRQTZ","created_at":"2026-05-18T12:25:56Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2008:B2LVRQTZEEZXKWCFDEWXDNQFTU","target":"record","payload":{"canonical_record":{"source":{"id":"0812.1474","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2008-12-08T11:58:18Z","cross_cats_sorted":[],"title_canon_sha256":"eb76aa48efa4e79902a2ad492affa3aada80dbe3b6d047711a6a70968133bd94","abstract_canon_sha256":"2d0ce4cc17ff1d0e7dcf4bdaba333e19ecebf446c316b5318c10e5283baa6fa1"},"schema_version":"1.0"},"canonical_sha256":"0e9758c2792133755845192d71b6059d0ab51479d5b1440776a8b69a3865e979","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:15:11.441068Z","signature_b64":"52rxQTUpEOhbeYsaaDns8mb4SSIrSJ9lzvD04yAF8fe12OnH1SIAR8aF0e9gpWKZMzqNmcV+XQb9NRFbeMWSAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0e9758c2792133755845192d71b6059d0ab51479d5b1440776a8b69a3865e979","last_reissued_at":"2026-05-18T02:15:11.440329Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:15:11.440329Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0812.1474","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":"2026-05-18T02:15:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"EVPgxO4Ii+MMH/xSHtozXKersKhlU5J/sW1YASy7880IarJwMrS3uREdDMaGcTeMkp+rm88aeCjHEVXq3cF2BA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T07:34:50.306716Z"},"content_sha256":"2af0cd939a8a916643dc1bfaf9e5ef007385a3cc4d8e6e9c43d2673e8316690d","schema_version":"1.0","event_id":"sha256:2af0cd939a8a916643dc1bfaf9e5ef007385a3cc4d8e6e9c43d2673e8316690d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2008:B2LVRQTZEEZXKWCFDEWXDNQFTU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Entropic uncertainties for joint quantum measurements","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Erika Andersson, Stephen M Barnett, Thomas Brougham","submitted_at":"2008-12-08T11:58:18Z","abstract_excerpt":"We investigate the uncertainty associated with a joint quantum measurement of two components of spin of a spin-1/2 particle and quantify this in terms of entropy. We consider two entropic quantities: the joint entropy and the sum of the marginal entropies, and obtain lower bounds for each of these quantities. For the case of joint measurements where we measure each spin observable equally well, these lower bounds are tight."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0812.1474","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":"2026-05-18T02:15:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4L6RvOhVkJsZ9TApD/aQxRFQU5V5pZpa6IZmNte0aQR1weoZ8hcsuOw/GQGFkxRSJ/Hsi0vfBBYJB2hs9XMeDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T07:34:50.307250Z"},"content_sha256":"1aa56a040a1502ef77208fe7bab54831a65940035e60c3b5025279feb86652e8","schema_version":"1.0","event_id":"sha256:1aa56a040a1502ef77208fe7bab54831a65940035e60c3b5025279feb86652e8"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/bundle.json","state_url":"https://pith.science/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/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":"2026-05-27T07:34:50Z","links":{"resolver":"https://pith.science/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU","bundle":"https://pith.science/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/bundle.json","state":"https://pith.science/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/B2LVRQTZEEZXKWCFDEWXDNQFTU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2008:B2LVRQTZEEZXKWCFDEWXDNQFTU","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":"2d0ce4cc17ff1d0e7dcf4bdaba333e19ecebf446c316b5318c10e5283baa6fa1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2008-12-08T11:58:18Z","title_canon_sha256":"eb76aa48efa4e79902a2ad492affa3aada80dbe3b6d047711a6a70968133bd94"},"schema_version":"1.0","source":{"id":"0812.1474","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0812.1474","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"arxiv_version","alias_value":"0812.1474v2","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0812.1474","created_at":"2026-05-18T02:15:11Z"},{"alias_kind":"pith_short_12","alias_value":"B2LVRQTZEEZX","created_at":"2026-05-18T12:25:56Z"},{"alias_kind":"pith_short_16","alias_value":"B2LVRQTZEEZXKWCF","created_at":"2026-05-18T12:25:56Z"},{"alias_kind":"pith_short_8","alias_value":"B2LVRQTZ","created_at":"2026-05-18T12:25:56Z"}],"graph_snapshots":[{"event_id":"sha256:1aa56a040a1502ef77208fe7bab54831a65940035e60c3b5025279feb86652e8","target":"graph","created_at":"2026-05-18T02:15:11Z","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 investigate the uncertainty associated with a joint quantum measurement of two components of spin of a spin-1/2 particle and quantify this in terms of entropy. We consider two entropic quantities: the joint entropy and the sum of the marginal entropies, and obtain lower bounds for each of these quantities. For the case of joint measurements where we measure each spin observable equally well, these lower bounds are tight.","authors_text":"Erika Andersson, Stephen M Barnett, Thomas Brougham","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2008-12-08T11:58:18Z","title":"Entropic uncertainties for joint quantum measurements"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0812.1474","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":"sha256:2af0cd939a8a916643dc1bfaf9e5ef007385a3cc4d8e6e9c43d2673e8316690d","target":"record","created_at":"2026-05-18T02:15:11Z","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":"2d0ce4cc17ff1d0e7dcf4bdaba333e19ecebf446c316b5318c10e5283baa6fa1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2008-12-08T11:58:18Z","title_canon_sha256":"eb76aa48efa4e79902a2ad492affa3aada80dbe3b6d047711a6a70968133bd94"},"schema_version":"1.0","source":{"id":"0812.1474","kind":"arxiv","version":2}},"canonical_sha256":"0e9758c2792133755845192d71b6059d0ab51479d5b1440776a8b69a3865e979","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0e9758c2792133755845192d71b6059d0ab51479d5b1440776a8b69a3865e979","first_computed_at":"2026-05-18T02:15:11.440329Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:15:11.440329Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"52rxQTUpEOhbeYsaaDns8mb4SSIrSJ9lzvD04yAF8fe12OnH1SIAR8aF0e9gpWKZMzqNmcV+XQb9NRFbeMWSAA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:15:11.441068Z","signed_message":"canonical_sha256_bytes"},"source_id":"0812.1474","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:2af0cd939a8a916643dc1bfaf9e5ef007385a3cc4d8e6e9c43d2673e8316690d","sha256:1aa56a040a1502ef77208fe7bab54831a65940035e60c3b5025279feb86652e8"],"state_sha256":"66c714ecc56de8edcb04d71c94ce51f6ce712b54a02f31988b9b9dff1491e621"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"aY4sE/hv2hb6IjaRQSD/RxmOzlO81ZkjeY28vwd54+h/QC2tt8YHtXUUdkaRIhrboBjVx1rC8cB8xR//QVUqAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T07:34:50.309765Z","bundle_sha256":"e9385eb98c5be25ea3005ec4c1ad20eb68e63fe9b72b78d4dde986d21b676867"}}