{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:DIQHYYHFZV5KQWNJLSM467WY2M","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":"69f74ab356420967d02156de4baf5ced8c031077de8e03101930e1e17927c24c","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-sa/4.0/","primary_cat":"cs.IR","submitted_at":"2026-05-22T21:24:14Z","title_canon_sha256":"233261facd46c726977603ba1546557d19faafa4fd23f1e6b0367925fbd41d9c"},"schema_version":"1.0","source":{"id":"2605.24236","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2605.24236","created_at":"2026-05-26T01:02:54Z"},{"alias_kind":"arxiv_version","alias_value":"2605.24236v1","created_at":"2026-05-26T01:02:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2605.24236","created_at":"2026-05-26T01:02:54Z"},{"alias_kind":"pith_short_12","alias_value":"DIQHYYHFZV5K","created_at":"2026-05-26T01:02:54Z"},{"alias_kind":"pith_short_16","alias_value":"DIQHYYHFZV5KQWNJ","created_at":"2026-05-26T01:02:54Z"},{"alias_kind":"pith_short_8","alias_value":"DIQHYYHF","created_at":"2026-05-26T01:02:54Z"}],"graph_snapshots":[{"event_id":"sha256:b26dffe2b42880b0c5cf621aeb7b0e51f76042af1a1756c8893220b78b61c3e1","target":"graph","created_at":"2026-05-26T01:02:54Z","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/2605.24236/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Identifying the scientific source behind a social media claim requires matching short, informal, and often multilingual claims against large collections of scientific publications, where semantically related papers may act as challenging distractors or false negatives during training. We present our submission to CheckThat! 2026 Task 1 on multilingual scientific-source retrieval, focusing on how hard-negative mining should be adapted to multi-stage retrieval pipelines for scientific-source retrieval. We propose cluster-aware hard-negative mining strategies that exploit the semantic structure o","authors_text":"Juli Bakagianni, Symeon Papadopoulos","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by-sa/4.0/","primary_cat":"cs.IR","submitted_at":"2026-05-22T21:24:14Z","title":"MeVer at CheckThat! 2026: Cluster-Aware Hard-Negative Mining for Multilingual Scientific-Source Retrieval"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.24236","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:aa3d0e76833348a3cbf1c4720c6e9a8129b667a4c0d9c467f88d4ab45c5fa148","target":"record","created_at":"2026-05-26T01:02:54Z","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":"69f74ab356420967d02156de4baf5ced8c031077de8e03101930e1e17927c24c","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-sa/4.0/","primary_cat":"cs.IR","submitted_at":"2026-05-22T21:24:14Z","title_canon_sha256":"233261facd46c726977603ba1546557d19faafa4fd23f1e6b0367925fbd41d9c"},"schema_version":"1.0","source":{"id":"2605.24236","kind":"arxiv","version":1}},"canonical_sha256":"1a207c60e5cd7aa859a95c99cf7ed8d3006db7a6d4573e17c07822dd129934e5","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1a207c60e5cd7aa859a95c99cf7ed8d3006db7a6d4573e17c07822dd129934e5","first_computed_at":"2026-05-26T01:02:54.159361Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-26T01:02:54.159361Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TFH8sOOpknYW4fMot8YyRf0UfFSS1e6QgaQd2qK5A82XN9ZDVAqNYMxkFnwjSCztH9LuSo4cjmXoYXFFSiGRAQ==","signature_status":"signed_v1","signed_at":"2026-05-26T01:02:54.160126Z","signed_message":"canonical_sha256_bytes"},"source_id":"2605.24236","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:aa3d0e76833348a3cbf1c4720c6e9a8129b667a4c0d9c467f88d4ab45c5fa148","sha256:b26dffe2b42880b0c5cf621aeb7b0e51f76042af1a1756c8893220b78b61c3e1"],"state_sha256":"979bdf4877911aa38904fa8d53bd91d4210c417c7a8e34b7ec306a09f6b03265"}