{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:MRDTHATZTKCJ2SYX6FVICHBG6L","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":"9e441b1b7f8ada05e590802f3b05255e0dd2fda078af9385bdac19afd321ae0e","cross_cats_sorted":["cs.CC","cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-24T17:09:20Z","title_canon_sha256":"7d32472bf9309a4600fce99eda7d133025311ed4bac143c50fb62bd2523bcf84"},"schema_version":"1.0","source":{"id":"2606.26034","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.26034","created_at":"2026-06-25T01:18:46Z"},{"alias_kind":"arxiv_version","alias_value":"2606.26034v1","created_at":"2026-06-25T01:18:46Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.26034","created_at":"2026-06-25T01:18:46Z"},{"alias_kind":"pith_short_12","alias_value":"MRDTHATZTKCJ","created_at":"2026-06-25T01:18:46Z"},{"alias_kind":"pith_short_16","alias_value":"MRDTHATZTKCJ2SYX","created_at":"2026-06-25T01:18:46Z"},{"alias_kind":"pith_short_8","alias_value":"MRDTHATZ","created_at":"2026-06-25T01:18:46Z"}],"graph_snapshots":[{"event_id":"sha256:8a87c997885086f9e6d26e6d42911fb0f364caa8c627c54d8a1724662029b08a","target":"graph","created_at":"2026-06-25T01:18:46Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2606.26034/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We consider the problem of estimating the fidelity of an unknown quantum state to a known reference state to within additive error $\\varepsilon$. We show that the sample complexity is $O(r^2/\\varepsilon^2)$ with optimal $\\varepsilon$-dependence when the reference state is of rank $r$, improving the previous best $O(r^2\\log^2(1/\\varepsilon)/\\varepsilon^4)$ due to Utsumi, Nakata, Wang, and Takagi (QIP 2026). We also provide a lower bound of $\\Omega(r/\\varepsilon^2)$, improving the previous best $\\Omega(r/\\varepsilon+1/\\varepsilon^2)$, with implications to quantum query complexity. Moreover, we f","authors_text":"Qisheng Wang","cross_cats":["cs.CC","cs.IT","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-24T17:09:20Z","title":"Estimating Fidelity to a Reference Quantum State"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.26034","kind":"arxiv","version":1},"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":"sha256:89a24f2bf1b980a94dcfcfc45f7035a32c1ea028fdc35980047dbf6324a8c1be","target":"record","created_at":"2026-06-25T01:18:46Z","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":"9e441b1b7f8ada05e590802f3b05255e0dd2fda078af9385bdac19afd321ae0e","cross_cats_sorted":["cs.CC","cs.IT","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-24T17:09:20Z","title_canon_sha256":"7d32472bf9309a4600fce99eda7d133025311ed4bac143c50fb62bd2523bcf84"},"schema_version":"1.0","source":{"id":"2606.26034","kind":"arxiv","version":1}},"canonical_sha256":"64473382799a849d4b17f16a811c26f2d7cd55497c75397721a5a756c406f9ef","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"64473382799a849d4b17f16a811c26f2d7cd55497c75397721a5a756c406f9ef","first_computed_at":"2026-06-25T01:18:46.398399Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-25T01:18:46.398399Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"+wNJPFDRv2F6S3494h+FvKynKHDS2iqBQIbjCwYbNtbFJQ3QSdbPx0oTDAfNlfLUQc8iM3RvsMBc4SxP2wF+CQ==","signature_status":"signed_v1","signed_at":"2026-06-25T01:18:46.398775Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.26034","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:89a24f2bf1b980a94dcfcfc45f7035a32c1ea028fdc35980047dbf6324a8c1be","sha256:8a87c997885086f9e6d26e6d42911fb0f364caa8c627c54d8a1724662029b08a"],"state_sha256":"4ed4fab570f5e5c6d0ece43498680cb1131efbbff57e851d4468d162441e396a"}