{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:IRBCOOK3UTXIBSXN4LMSAYVIMW","short_pith_number":"pith:IRBCOOK3","canonical_record":{"source":{"id":"1211.7224","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-11-30T12:03:02Z","cross_cats_sorted":[],"title_canon_sha256":"720d4239cdbc01e486d90f986ef0c948d890c12b7c4270fda207948a05759d5b","abstract_canon_sha256":"59dfe996a52375586fa757f605a3cee5f0d5f818ee20c10a3d0695b05f8abaa0"},"schema_version":"1.0"},"canonical_sha256":"444227395ba4ee80caede2d92062a865b28936de1b09d0108f43b858ca316a9e","source":{"kind":"arxiv","id":"1211.7224","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1211.7224","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"arxiv_version","alias_value":"1211.7224v4","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1211.7224","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"pith_short_12","alias_value":"IRBCOOK3UTXI","created_at":"2026-05-18T12:27:09Z"},{"alias_kind":"pith_short_16","alias_value":"IRBCOOK3UTXIBSXN","created_at":"2026-05-18T12:27:09Z"},{"alias_kind":"pith_short_8","alias_value":"IRBCOOK3","created_at":"2026-05-18T12:27:09Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:IRBCOOK3UTXIBSXN4LMSAYVIMW","target":"record","payload":{"canonical_record":{"source":{"id":"1211.7224","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-11-30T12:03:02Z","cross_cats_sorted":[],"title_canon_sha256":"720d4239cdbc01e486d90f986ef0c948d890c12b7c4270fda207948a05759d5b","abstract_canon_sha256":"59dfe996a52375586fa757f605a3cee5f0d5f818ee20c10a3d0695b05f8abaa0"},"schema_version":"1.0"},"canonical_sha256":"444227395ba4ee80caede2d92062a865b28936de1b09d0108f43b858ca316a9e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:44:33.418991Z","signature_b64":"OvtHq590GGyoNj2Mv7Xjp0Y2CdK4Xh5JQh8kas3rkMa7tAe+/cgOYOyGqARtX88n5s/CleWgaEd6S5kz6+24Dg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"444227395ba4ee80caede2d92062a865b28936de1b09d0108f43b858ca316a9e","last_reissued_at":"2026-05-17T23:44:33.418492Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:44:33.418492Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1211.7224","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:44:33Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"U7Pxzc2+uUG4T9xbd2E2MaB1xH/d6GzupFkYA5zDRGZr8nXOS6EtTDyngsGJ/lhXN74Mla3sv2POhd2d5kQdBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-23T08:09:44.285943Z"},"content_sha256":"0d5c79df39f1f6935dae8ba6c3e2ab7f845b1529054ba6afecd608d52cc08ab6","schema_version":"1.0","event_id":"sha256:0d5c79df39f1f6935dae8ba6c3e2ab7f845b1529054ba6afecd608d52cc08ab6"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:IRBCOOK3UTXIBSXN4LMSAYVIMW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Quantum estimation of a two-phase spin rotation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Cyril Vaneph, Marco G. Genoni, Tommaso Tufarelli","submitted_at":"2012-11-30T12:03:02Z","abstract_excerpt":"We study the estimation of an infinitesimal rotation of a spin-j system, characterized by two unknown phases, and compare the estimation precision achievable with two different strategies. The first is a standard `joint estimation' strategy, in which a single probe state is used to estimate both parameters, while the second is a `sequential' strategy in which the two phases are estimated separately, each on half of the total number of system copies. In the limit of small angles we show that, although the joint estimation approach yields in general a better performance, the two strategies posse"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1211.7224","kind":"arxiv","version":4},"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":"2026-05-17T23:44:33Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"c/FMA6Z+9oMwJLJ35jcu4zwYCEWAcU6rfh+7YBXieI+VtzNOkVdxb7ZrbOGF8zj2Xvs29E0/JpmtOb4vTreFAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-23T08:09:44.286618Z"},"content_sha256":"e5c8b00c9b73b2ae68e02663cd4a26238d8f3d5d7ea0257beca715ac8719196a","schema_version":"1.0","event_id":"sha256:e5c8b00c9b73b2ae68e02663cd4a26238d8f3d5d7ea0257beca715ac8719196a"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/bundle.json","state_url":"https://pith.science/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/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":"2026-05-23T08:09:44Z","links":{"resolver":"https://pith.science/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW","bundle":"https://pith.science/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/bundle.json","state":"https://pith.science/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IRBCOOK3UTXIBSXN4LMSAYVIMW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:IRBCOOK3UTXIBSXN4LMSAYVIMW","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":"59dfe996a52375586fa757f605a3cee5f0d5f818ee20c10a3d0695b05f8abaa0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-11-30T12:03:02Z","title_canon_sha256":"720d4239cdbc01e486d90f986ef0c948d890c12b7c4270fda207948a05759d5b"},"schema_version":"1.0","source":{"id":"1211.7224","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1211.7224","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"arxiv_version","alias_value":"1211.7224v4","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1211.7224","created_at":"2026-05-17T23:44:33Z"},{"alias_kind":"pith_short_12","alias_value":"IRBCOOK3UTXI","created_at":"2026-05-18T12:27:09Z"},{"alias_kind":"pith_short_16","alias_value":"IRBCOOK3UTXIBSXN","created_at":"2026-05-18T12:27:09Z"},{"alias_kind":"pith_short_8","alias_value":"IRBCOOK3","created_at":"2026-05-18T12:27:09Z"}],"graph_snapshots":[{"event_id":"sha256:e5c8b00c9b73b2ae68e02663cd4a26238d8f3d5d7ea0257beca715ac8719196a","target":"graph","created_at":"2026-05-17T23:44:33Z","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 study the estimation of an infinitesimal rotation of a spin-j system, characterized by two unknown phases, and compare the estimation precision achievable with two different strategies. The first is a standard `joint estimation' strategy, in which a single probe state is used to estimate both parameters, while the second is a `sequential' strategy in which the two phases are estimated separately, each on half of the total number of system copies. In the limit of small angles we show that, although the joint estimation approach yields in general a better performance, the two strategies posse","authors_text":"Cyril Vaneph, Marco G. Genoni, Tommaso Tufarelli","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-11-30T12:03:02Z","title":"Quantum estimation of a two-phase spin rotation"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1211.7224","kind":"arxiv","version":4},"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":"sha256:0d5c79df39f1f6935dae8ba6c3e2ab7f845b1529054ba6afecd608d52cc08ab6","target":"record","created_at":"2026-05-17T23:44:33Z","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":"59dfe996a52375586fa757f605a3cee5f0d5f818ee20c10a3d0695b05f8abaa0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-11-30T12:03:02Z","title_canon_sha256":"720d4239cdbc01e486d90f986ef0c948d890c12b7c4270fda207948a05759d5b"},"schema_version":"1.0","source":{"id":"1211.7224","kind":"arxiv","version":4}},"canonical_sha256":"444227395ba4ee80caede2d92062a865b28936de1b09d0108f43b858ca316a9e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"444227395ba4ee80caede2d92062a865b28936de1b09d0108f43b858ca316a9e","first_computed_at":"2026-05-17T23:44:33.418492Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:44:33.418492Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"OvtHq590GGyoNj2Mv7Xjp0Y2CdK4Xh5JQh8kas3rkMa7tAe+/cgOYOyGqARtX88n5s/CleWgaEd6S5kz6+24Dg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:44:33.418991Z","signed_message":"canonical_sha256_bytes"},"source_id":"1211.7224","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0d5c79df39f1f6935dae8ba6c3e2ab7f845b1529054ba6afecd608d52cc08ab6","sha256:e5c8b00c9b73b2ae68e02663cd4a26238d8f3d5d7ea0257beca715ac8719196a"],"state_sha256":"30929d134042a44520bc62a53370522115b06accb64a03e448308df466d86cc0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5EXTPzEQvWq93+gFwnPoauB9OD1pw02Efwy9FoiTSj/6eQprg/oLBFZy5Zf+AZ1Am/LJKdLSMAilGVd+LIFgCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-23T08:09:44.290777Z","bundle_sha256":"a906e3e4fb1a4b37f8442266f064f63ada28a200b577d4a9b341bf01f669e838"}}