{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:2BPQZ7M6AAPGBPAUEADSYZ2MVD","short_pith_number":"pith:2BPQZ7M6","canonical_record":{"source":{"id":"1605.01280","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.AG","submitted_at":"2016-05-04T13:50:15Z","cross_cats_sorted":[],"title_canon_sha256":"4d592e098e22d9a9b0ca96aacd57c2ef2e8c4d183c749a531755e5d6837700d7","abstract_canon_sha256":"c85d72310299f7e4c156bc6c6d9bf1dcfedcf340ea1b48cca2f7eb4f7bdd07be"},"schema_version":"1.0"},"canonical_sha256":"d05f0cfd9e001e60bc1420072c674ca8eff1d5721739e43830d8cb4bddeaeb98","source":{"kind":"arxiv","id":"1605.01280","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1605.01280","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"arxiv_version","alias_value":"1605.01280v3","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1605.01280","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"pith_short_12","alias_value":"2BPQZ7M6AAPG","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_16","alias_value":"2BPQZ7M6AAPGBPAU","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_8","alias_value":"2BPQZ7M6","created_at":"2026-05-18T12:29:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:2BPQZ7M6AAPGBPAUEADSYZ2MVD","target":"record","payload":{"canonical_record":{"source":{"id":"1605.01280","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.AG","submitted_at":"2016-05-04T13:50:15Z","cross_cats_sorted":[],"title_canon_sha256":"4d592e098e22d9a9b0ca96aacd57c2ef2e8c4d183c749a531755e5d6837700d7","abstract_canon_sha256":"c85d72310299f7e4c156bc6c6d9bf1dcfedcf340ea1b48cca2f7eb4f7bdd07be"},"schema_version":"1.0"},"canonical_sha256":"d05f0cfd9e001e60bc1420072c674ca8eff1d5721739e43830d8cb4bddeaeb98","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:24:35.604563Z","signature_b64":"TRc2i3XZIWub97UMyjDzyzE6PSEc/WlDl5alTsRdBnhJhWxLjtso26Acu0XTZKParxelQED6QMIP3MAKGK64Cw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d05f0cfd9e001e60bc1420072c674ca8eff1d5721739e43830d8cb4bddeaeb98","last_reissued_at":"2026-05-18T00:24:35.604098Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:24:35.604098Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1605.01280","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:24:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"RQoUixCKEte+MY3lzlpCtxVwIegYXlBIxP8DXDj06SFjlH4vkrw1VJ85wTam5BmXolMftWiQGyVh7wyBvH9eCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-11T23:14:44.915831Z"},"content_sha256":"e3d0870ade038e91cf33c7f2a8f50924ff0198d0f4e2072873b4959e82844f8b","schema_version":"1.0","event_id":"sha256:e3d0870ade038e91cf33c7f2a8f50924ff0198d0f4e2072873b4959e82844f8b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:2BPQZ7M6AAPGBPAUEADSYZ2MVD","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Torsion exceptional sheaves on weak del Pezzo surfaces of Type A","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.AG","authors_text":"Chen Jiang, Pu Cao","submitted_at":"2016-05-04T13:50:15Z","abstract_excerpt":"We investigate torsion exceptional sheaves on a weak del Pezzo surface of degree greater than two whose anticanonical model has at most $A_n$-singularities. We show that every torsion exceptional sheaf can be obtained from a line bundle on a $(-1)$-curve by acting spherical twist functors successively."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1605.01280","kind":"arxiv","version":3},"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":"2026-05-18T00:24:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1zLzwMgbrq5n94MrtvW7d4b4u5g/g56bSRPHMVqSkE2VWh1RGB+KmKiuWpmao144zm6smRMwTfMDT0ELNDcRBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-11T23:14:44.916526Z"},"content_sha256":"37daeb0346a1f102ab5f4ca6b6556ba55d64fb5dcc34a56be9fdcfd87283d623","schema_version":"1.0","event_id":"sha256:37daeb0346a1f102ab5f4ca6b6556ba55d64fb5dcc34a56be9fdcfd87283d623"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/bundle.json","state_url":"https://pith.science/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/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":"2026-06-11T23:14:44Z","links":{"resolver":"https://pith.science/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD","bundle":"https://pith.science/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/bundle.json","state":"https://pith.science/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/state.json","well_known_bundle":"https://pith.science/.well-known/pith/2BPQZ7M6AAPGBPAUEADSYZ2MVD/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:2BPQZ7M6AAPGBPAUEADSYZ2MVD","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":"c85d72310299f7e4c156bc6c6d9bf1dcfedcf340ea1b48cca2f7eb4f7bdd07be","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.AG","submitted_at":"2016-05-04T13:50:15Z","title_canon_sha256":"4d592e098e22d9a9b0ca96aacd57c2ef2e8c4d183c749a531755e5d6837700d7"},"schema_version":"1.0","source":{"id":"1605.01280","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1605.01280","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"arxiv_version","alias_value":"1605.01280v3","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1605.01280","created_at":"2026-05-18T00:24:35Z"},{"alias_kind":"pith_short_12","alias_value":"2BPQZ7M6AAPG","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_16","alias_value":"2BPQZ7M6AAPGBPAU","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_8","alias_value":"2BPQZ7M6","created_at":"2026-05-18T12:29:52Z"}],"graph_snapshots":[{"event_id":"sha256:37daeb0346a1f102ab5f4ca6b6556ba55d64fb5dcc34a56be9fdcfd87283d623","target":"graph","created_at":"2026-05-18T00:24:35Z","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 torsion exceptional sheaves on a weak del Pezzo surface of degree greater than two whose anticanonical model has at most $A_n$-singularities. We show that every torsion exceptional sheaf can be obtained from a line bundle on a $(-1)$-curve by acting spherical twist functors successively.","authors_text":"Chen Jiang, Pu Cao","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.AG","submitted_at":"2016-05-04T13:50:15Z","title":"Torsion exceptional sheaves on weak del Pezzo surfaces of Type A"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1605.01280","kind":"arxiv","version":3},"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:e3d0870ade038e91cf33c7f2a8f50924ff0198d0f4e2072873b4959e82844f8b","target":"record","created_at":"2026-05-18T00:24:35Z","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":"c85d72310299f7e4c156bc6c6d9bf1dcfedcf340ea1b48cca2f7eb4f7bdd07be","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.AG","submitted_at":"2016-05-04T13:50:15Z","title_canon_sha256":"4d592e098e22d9a9b0ca96aacd57c2ef2e8c4d183c749a531755e5d6837700d7"},"schema_version":"1.0","source":{"id":"1605.01280","kind":"arxiv","version":3}},"canonical_sha256":"d05f0cfd9e001e60bc1420072c674ca8eff1d5721739e43830d8cb4bddeaeb98","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d05f0cfd9e001e60bc1420072c674ca8eff1d5721739e43830d8cb4bddeaeb98","first_computed_at":"2026-05-18T00:24:35.604098Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:24:35.604098Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TRc2i3XZIWub97UMyjDzyzE6PSEc/WlDl5alTsRdBnhJhWxLjtso26Acu0XTZKParxelQED6QMIP3MAKGK64Cw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:24:35.604563Z","signed_message":"canonical_sha256_bytes"},"source_id":"1605.01280","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e3d0870ade038e91cf33c7f2a8f50924ff0198d0f4e2072873b4959e82844f8b","sha256:37daeb0346a1f102ab5f4ca6b6556ba55d64fb5dcc34a56be9fdcfd87283d623"],"state_sha256":"bbce70bc9cb5e2f2b1eb5152737d58da96a6935b4c5d93df9dd6cf029140e0c5"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n08OGJJXVu4qk+DU5sD4LnVQzifR/eNItJWR9TyhP/vgE0hIdJButhSwWZ5aQpSPwc3ZzaiA/W1P3Uo/A3dXBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-11T23:14:44.920349Z","bundle_sha256":"34569375a4aca2449a53597c1f1a51a993dec7df44c7b913fb67951220854861"}}