{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:RQKQYQX3WY7PHCQPCOB6233QQ7","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":"a32cbf1758644d9436d5d75b2927ef16d325659af0ca06ed09a10f0be49245e1","cross_cats_sorted":["math.OC","physics.geo-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.comp-ph","submitted_at":"2026-06-09T13:25:01Z","title_canon_sha256":"2d313223b9062b550a4b9a8ac2f04cd523ab4b863991ca4c6cbf80b952fad6a4"},"schema_version":"1.0","source":{"id":"2606.10836","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.10836","created_at":"2026-06-10T01:10:43Z"},{"alias_kind":"arxiv_version","alias_value":"2606.10836v1","created_at":"2026-06-10T01:10:43Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.10836","created_at":"2026-06-10T01:10:43Z"},{"alias_kind":"pith_short_12","alias_value":"RQKQYQX3WY7P","created_at":"2026-06-10T01:10:43Z"},{"alias_kind":"pith_short_16","alias_value":"RQKQYQX3WY7PHCQP","created_at":"2026-06-10T01:10:43Z"},{"alias_kind":"pith_short_8","alias_value":"RQKQYQX3","created_at":"2026-06-10T01:10:43Z"}],"graph_snapshots":[{"event_id":"sha256:1c0ba424d0669fc2c862185be046e2dd72b3563c5feb9e826207f74b344ef2c3","target":"graph","created_at":"2026-06-10T01:10:43Z","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/2606.10836/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Groundwater models are routinely non-identifiable: sparse subsurface observations leave many combinations of parameters, states, and boundary conditions equally consistent with the available data. Existing uncertainty quantification (UQ) methods address this by exploring a finite set of model realizations, but incomplete exploration can systematically underestimate the true range of admissible solutions. We propose a fundamentally different approach based on Optimization-based Bound Tightening (OBBT), which represents uncertainty directly as intervals and tightens them by extremizing variables","authors_text":"Ksenia Bestuzheva, Maximilian Ramgraber","cross_cats":["math.OC","physics.geo-ph"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.comp-ph","submitted_at":"2026-06-09T13:25:01Z","title":"Bounding the Null Space: Interval-Based Uncertainty Quantification for Non-Identifiable Groundwater Models"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.10836","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":"sha256:13ffe6bf5e1e3b849be14c0e72ef93fc6670a58d4da3d6675df3f1afa4df1bb7","target":"record","created_at":"2026-06-10T01:10:43Z","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":"a32cbf1758644d9436d5d75b2927ef16d325659af0ca06ed09a10f0be49245e1","cross_cats_sorted":["math.OC","physics.geo-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.comp-ph","submitted_at":"2026-06-09T13:25:01Z","title_canon_sha256":"2d313223b9062b550a4b9a8ac2f04cd523ab4b863991ca4c6cbf80b952fad6a4"},"schema_version":"1.0","source":{"id":"2606.10836","kind":"arxiv","version":1}},"canonical_sha256":"8c150c42fbb63ef38a0f1383ed6f7087e34e2c35b588dbea3c4ac46f8fac305a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8c150c42fbb63ef38a0f1383ed6f7087e34e2c35b588dbea3c4ac46f8fac305a","first_computed_at":"2026-06-10T01:10:43.166557Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-10T01:10:43.166557Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"5oV72gQA//gR3IOvYDWszrNf+GcNs2NubI59tDOybi1op/KUISuiwmjDW5e7bcO13VhjZKxXjJ9LPfjvlWtVAQ==","signature_status":"signed_v1","signed_at":"2026-06-10T01:10:43.167171Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.10836","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:13ffe6bf5e1e3b849be14c0e72ef93fc6670a58d4da3d6675df3f1afa4df1bb7","sha256:1c0ba424d0669fc2c862185be046e2dd72b3563c5feb9e826207f74b344ef2c3"],"state_sha256":"f2b740ef9ea07a571147d3afd5e6b99588c88cc3bc2a57d190925a67a04b57d8"}