{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:JSFH6W4KOJNV5K3BQFLJKUXVKX","short_pith_number":"pith:JSFH6W4K","canonical_record":{"source":{"id":"1609.07415","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.ST","submitted_at":"2016-09-23T16:15:47Z","cross_cats_sorted":["cs.IT","math.IT","stat.TH"],"title_canon_sha256":"5d02912f29db6e47f6ad7403eb4050ce1bbbf693f204cb1135e0a8b2e4af5c33","abstract_canon_sha256":"2a2406b69d48a1b525729616e1262be99b3b4484456c336ce1b5b1e2724ace31"},"schema_version":"1.0"},"canonical_sha256":"4c8a7f5b8a725b5eab6181569552f555f68967912b50bd846ea7c5df6e796586","source":{"kind":"arxiv","id":"1609.07415","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1609.07415","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"arxiv_version","alias_value":"1609.07415v1","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1609.07415","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"pith_short_12","alias_value":"JSFH6W4KOJNV","created_at":"2026-05-18T12:30:25Z"},{"alias_kind":"pith_short_16","alias_value":"JSFH6W4KOJNV5K3B","created_at":"2026-05-18T12:30:25Z"},{"alias_kind":"pith_short_8","alias_value":"JSFH6W4K","created_at":"2026-05-18T12:30:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:JSFH6W4KOJNV5K3BQFLJKUXVKX","target":"record","payload":{"canonical_record":{"source":{"id":"1609.07415","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.ST","submitted_at":"2016-09-23T16:15:47Z","cross_cats_sorted":["cs.IT","math.IT","stat.TH"],"title_canon_sha256":"5d02912f29db6e47f6ad7403eb4050ce1bbbf693f204cb1135e0a8b2e4af5c33","abstract_canon_sha256":"2a2406b69d48a1b525729616e1262be99b3b4484456c336ce1b5b1e2724ace31"},"schema_version":"1.0"},"canonical_sha256":"4c8a7f5b8a725b5eab6181569552f555f68967912b50bd846ea7c5df6e796586","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:04:00.916871Z","signature_b64":"lbaN3Ye5Zmf7URGYqJfLbX0wTssFVzZo+WnVaBNRRYiCj0z//J4neuP+yOyn6eukfy1m1HCa31qVIaJHzyyaAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"4c8a7f5b8a725b5eab6181569552f555f68967912b50bd846ea7c5df6e796586","last_reissued_at":"2026-05-18T01:04:00.916240Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:04:00.916240Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1609.07415","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:04:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sr4xRM816sjcyH30VT76donRiTyJOkLD/mN+Lz6+KlzaV7zTQb4a5PLiklc1h3lsb0aadxtGpTQ6KTh0UgiDDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-22T07:54:37.416201Z"},"content_sha256":"d60e8eb1bfe3ab941110bcdf6aa16df5d6f8b4e68378510cbcdc7f7973458c7a","schema_version":"1.0","event_id":"sha256:d60e8eb1bfe3ab941110bcdf6aa16df5d6f8b4e68378510cbcdc7f7973458c7a"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:JSFH6W4KOJNV5K3BQFLJKUXVKX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"On the Non-Existence of Unbiased Estimators in Constrained Estimation Problems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.IT","math.IT","stat.TH"],"primary_cat":"math.ST","authors_text":"Amir Leshem, Anelia Somekh-Baruch, Venkatesh Saligrama","submitted_at":"2016-09-23T16:15:47Z","abstract_excerpt":"We address the problem of existence of unbiased constrained parameter estimators. We show that if the constrained set of parameters is compact and the hypothesized distributions are absolutely continuous with respect to one another, then there exists no unbiased estimator. Weaker conditions for the absence of unbiased constrained estimators are also specified. We provide several examples which demonstrate the utility of these conditions."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.07415","kind":"arxiv","version":1},"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":"2026-05-18T01:04:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YdYJCXSDDIJfuCVE0kLfxizm+VRQbEPMlumtR+D2fVuvPUYilfbSL6iSJoBrS7i2LJVnjYqHHivcSeYdZDmlDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-22T07:54:37.416566Z"},"content_sha256":"0b71d2edd22fa5173a99ebaeaec8e23fbc633785b541255d5728e27313049232","schema_version":"1.0","event_id":"sha256:0b71d2edd22fa5173a99ebaeaec8e23fbc633785b541255d5728e27313049232"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/bundle.json","state_url":"https://pith.science/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/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":"2026-06-22T07:54:37Z","links":{"resolver":"https://pith.science/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX","bundle":"https://pith.science/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/bundle.json","state":"https://pith.science/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/JSFH6W4KOJNV5K3BQFLJKUXVKX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:JSFH6W4KOJNV5K3BQFLJKUXVKX","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":"2a2406b69d48a1b525729616e1262be99b3b4484456c336ce1b5b1e2724ace31","cross_cats_sorted":["cs.IT","math.IT","stat.TH"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.ST","submitted_at":"2016-09-23T16:15:47Z","title_canon_sha256":"5d02912f29db6e47f6ad7403eb4050ce1bbbf693f204cb1135e0a8b2e4af5c33"},"schema_version":"1.0","source":{"id":"1609.07415","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1609.07415","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"arxiv_version","alias_value":"1609.07415v1","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1609.07415","created_at":"2026-05-18T01:04:00Z"},{"alias_kind":"pith_short_12","alias_value":"JSFH6W4KOJNV","created_at":"2026-05-18T12:30:25Z"},{"alias_kind":"pith_short_16","alias_value":"JSFH6W4KOJNV5K3B","created_at":"2026-05-18T12:30:25Z"},{"alias_kind":"pith_short_8","alias_value":"JSFH6W4K","created_at":"2026-05-18T12:30:25Z"}],"graph_snapshots":[{"event_id":"sha256:0b71d2edd22fa5173a99ebaeaec8e23fbc633785b541255d5728e27313049232","target":"graph","created_at":"2026-05-18T01:04:00Z","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 address the problem of existence of unbiased constrained parameter estimators. We show that if the constrained set of parameters is compact and the hypothesized distributions are absolutely continuous with respect to one another, then there exists no unbiased estimator. Weaker conditions for the absence of unbiased constrained estimators are also specified. We provide several examples which demonstrate the utility of these conditions.","authors_text":"Amir Leshem, Anelia Somekh-Baruch, Venkatesh Saligrama","cross_cats":["cs.IT","math.IT","stat.TH"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.ST","submitted_at":"2016-09-23T16:15:47Z","title":"On the Non-Existence of Unbiased Estimators in Constrained Estimation Problems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.07415","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:d60e8eb1bfe3ab941110bcdf6aa16df5d6f8b4e68378510cbcdc7f7973458c7a","target":"record","created_at":"2026-05-18T01:04:00Z","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":"2a2406b69d48a1b525729616e1262be99b3b4484456c336ce1b5b1e2724ace31","cross_cats_sorted":["cs.IT","math.IT","stat.TH"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.ST","submitted_at":"2016-09-23T16:15:47Z","title_canon_sha256":"5d02912f29db6e47f6ad7403eb4050ce1bbbf693f204cb1135e0a8b2e4af5c33"},"schema_version":"1.0","source":{"id":"1609.07415","kind":"arxiv","version":1}},"canonical_sha256":"4c8a7f5b8a725b5eab6181569552f555f68967912b50bd846ea7c5df6e796586","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4c8a7f5b8a725b5eab6181569552f555f68967912b50bd846ea7c5df6e796586","first_computed_at":"2026-05-18T01:04:00.916240Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:04:00.916240Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lbaN3Ye5Zmf7URGYqJfLbX0wTssFVzZo+WnVaBNRRYiCj0z//J4neuP+yOyn6eukfy1m1HCa31qVIaJHzyyaAg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:04:00.916871Z","signed_message":"canonical_sha256_bytes"},"source_id":"1609.07415","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d60e8eb1bfe3ab941110bcdf6aa16df5d6f8b4e68378510cbcdc7f7973458c7a","sha256:0b71d2edd22fa5173a99ebaeaec8e23fbc633785b541255d5728e27313049232"],"state_sha256":"0dba4851600c7dc6d744ce0d54fc29fdd1a6695460fdce6fe33e7532e2b10f78"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FBgNi+1KKq0yfY+uLOldccTQrv/FBLfGgOYThYmMl17JlYyLUZTUQO09x7s3X/VJJjxqIy8gS7O13DL81xrRCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-22T07:54:37.418738Z","bundle_sha256":"f85f6c998b883d179b10df04a9462a1b2e075aad99d93cb7cd00a147e42685dd"}}