{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2017:FTRACFKJ5HXTKDHNOY4UELQ2UU","short_pith_number":"pith:FTRACFKJ","schema_version":"1.0","canonical_sha256":"2ce2011549e9ef350ced7639422e1aa504354c7873e232389b8e3fb6b8d31138","source":{"kind":"arxiv","id":"1708.04941","version":2},"attestation_state":"computed","paper":{"title":"Minimax estimation of qubit states with Bures risk","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math-ph","math.MP","stat.AP"],"primary_cat":"quant-ph","authors_text":"Anirudh Acharya, Madalin Guta","submitted_at":"2017-08-16T15:32:38Z","abstract_excerpt":"The central problem of quantum statistics is to devise measurement schemes for the estimation of an unknown state, given an ensemble of $n$ independent identically prepared systems. For locally quadratic loss functions, the risk of standard procedures has the usual scaling of $1/n$. However, it has been noticed that for fidelity based metrics such as the Bures distance, the risk of conventional (non-adaptive) qubit tomography schemes scales as $1/\\sqrt{n}$ for states close to the boundary of the Bloch sphere. Several proposed estimators appear to improve this scaling, and our goal is to analys"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1708.04941","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2017-08-16T15:32:38Z","cross_cats_sorted":["math-ph","math.MP","stat.AP"],"title_canon_sha256":"0fa3834d71d1d656bc597b86028b0cac585935a6c463c4a4197a8a49a4be7ba8","abstract_canon_sha256":"b629a2311c946c5ef19457b8fa48aec8e55d10ffd3975adadfce90caddf7f802"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:57:03.294881Z","signature_b64":"JW/2OlEUHENPshhKwsr1bqj+7aIq6EYKPDqT65k8VUik6mT+E7a6NUc65uizRUb5A1WOSnYldDKfXCFhi1TWAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2ce2011549e9ef350ced7639422e1aa504354c7873e232389b8e3fb6b8d31138","last_reissued_at":"2026-05-17T23:57:03.294205Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:57:03.294205Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Minimax estimation of qubit states with Bures risk","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math-ph","math.MP","stat.AP"],"primary_cat":"quant-ph","authors_text":"Anirudh Acharya, Madalin Guta","submitted_at":"2017-08-16T15:32:38Z","abstract_excerpt":"The central problem of quantum statistics is to devise measurement schemes for the estimation of an unknown state, given an ensemble of $n$ independent identically prepared systems. For locally quadratic loss functions, the risk of standard procedures has the usual scaling of $1/n$. However, it has been noticed that for fidelity based metrics such as the Bures distance, the risk of conventional (non-adaptive) qubit tomography schemes scales as $1/\\sqrt{n}$ for states close to the boundary of the Bloch sphere. Several proposed estimators appear to improve this scaling, and our goal is to analys"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1708.04941","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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1708.04941","created_at":"2026-05-17T23:57:03.294336+00:00"},{"alias_kind":"arxiv_version","alias_value":"1708.04941v2","created_at":"2026-05-17T23:57:03.294336+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1708.04941","created_at":"2026-05-17T23:57:03.294336+00:00"},{"alias_kind":"pith_short_12","alias_value":"FTRACFKJ5HXT","created_at":"2026-05-18T12:31:15.632608+00:00"},{"alias_kind":"pith_short_16","alias_value":"FTRACFKJ5HXTKDHN","created_at":"2026-05-18T12:31:15.632608+00:00"},{"alias_kind":"pith_short_8","alias_value":"FTRACFKJ","created_at":"2026-05-18T12:31:15.632608+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU","json":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU.json","graph_json":"https://pith.science/api/pith-number/FTRACFKJ5HXTKDHNOY4UELQ2UU/graph.json","events_json":"https://pith.science/api/pith-number/FTRACFKJ5HXTKDHNOY4UELQ2UU/events.json","paper":"https://pith.science/paper/FTRACFKJ"},"agent_actions":{"view_html":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU","download_json":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU.json","view_paper":"https://pith.science/paper/FTRACFKJ","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1708.04941&json=true","fetch_graph":"https://pith.science/api/pith-number/FTRACFKJ5HXTKDHNOY4UELQ2UU/graph.json","fetch_events":"https://pith.science/api/pith-number/FTRACFKJ5HXTKDHNOY4UELQ2UU/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU/action/timestamp_anchor","attest_storage":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU/action/storage_attestation","attest_author":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU/action/author_attestation","sign_citation":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU/action/citation_signature","submit_replication":"https://pith.science/pith/FTRACFKJ5HXTKDHNOY4UELQ2UU/action/replication_record"}},"created_at":"2026-05-17T23:57:03.294336+00:00","updated_at":"2026-05-17T23:57:03.294336+00:00"}