{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:CWHD525WY6R5ZK5T3GTY46RM5W","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":"9cdcac0542ea731fb83d8a96a4fb6f5b33f03acc7785c4693871b3e30f25c21f","cross_cats_sorted":["cs.NA","math.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2025-09-15T14:08:56Z","title_canon_sha256":"490fb878a789581e59dc6db7a406ac3c8e8aa2adfa864d13fc81f2e061949430"},"schema_version":"1.0","source":{"id":"2509.11951","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2509.11951","created_at":"2026-06-19T16:12:47Z"},{"alias_kind":"arxiv_version","alias_value":"2509.11951v2","created_at":"2026-06-19T16:12:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2509.11951","created_at":"2026-06-19T16:12:47Z"},{"alias_kind":"pith_short_12","alias_value":"CWHD525WY6R5","created_at":"2026-06-19T16:12:47Z"},{"alias_kind":"pith_short_16","alias_value":"CWHD525WY6R5ZK5T","created_at":"2026-06-19T16:12:47Z"},{"alias_kind":"pith_short_8","alias_value":"CWHD525W","created_at":"2026-06-19T16:12:47Z"}],"graph_snapshots":[{"event_id":"sha256:7f3328a57cfc9674591009075715f8aebc2f4df57aeaf21171ce91815bb88991","target":"graph","created_at":"2026-06-19T16:12:47Z","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/2509.11951/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We study an inverse boundary value problem for the nonlinear wave equation in $2 + 1$ dimensions. The objective is to recover an unknown potential $q(x, t)$ from the associated Dirichlet-to-Neumann map using real-valued waves. We propose a direct numerical reconstruction method for the Radon transform of $q$, which can then be inverted using standard X-ray tomography techniques to determine $q$. Our implementation introduces a spectral regularization procedure to stabilize the numerical differentiation step required in the reconstruction, improving robustness with respect to noise in the bound","authors_text":"Markus Harju, Suvi Anttila, Teemu Tyni","cross_cats":["cs.NA","math.AP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2025-09-15T14:08:56Z","title":"X-ray imaging from nonlinear waves: numerical reconstruction of a cubic nonlinearity"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2509.11951","kind":"arxiv","version":2},"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:d62c3fec08ad22e1fd3f5f3a06c3431987b9633c8b44ce02808188dd5222cf34","target":"record","created_at":"2026-06-19T16:12:47Z","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":"9cdcac0542ea731fb83d8a96a4fb6f5b33f03acc7785c4693871b3e30f25c21f","cross_cats_sorted":["cs.NA","math.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2025-09-15T14:08:56Z","title_canon_sha256":"490fb878a789581e59dc6db7a406ac3c8e8aa2adfa864d13fc81f2e061949430"},"schema_version":"1.0","source":{"id":"2509.11951","kind":"arxiv","version":2}},"canonical_sha256":"158e3eebb6c7a3dcabb3d9a78e7a2cedbcd31ae3a4f79eb363c89df151ce06e1","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"158e3eebb6c7a3dcabb3d9a78e7a2cedbcd31ae3a4f79eb363c89df151ce06e1","first_computed_at":"2026-06-19T16:12:47.762083Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-19T16:12:47.762083Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"FAzhekxmuZNIBc93Fy2wDRgN/00R6Z5fo48H/MwpDmf4rzZeeK6JxO+lHgMRidT8G7Tg7B9shtL12+3LRcV8Ag==","signature_status":"signed_v1","signed_at":"2026-06-19T16:12:47.762506Z","signed_message":"canonical_sha256_bytes"},"source_id":"2509.11951","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d62c3fec08ad22e1fd3f5f3a06c3431987b9633c8b44ce02808188dd5222cf34","sha256:7f3328a57cfc9674591009075715f8aebc2f4df57aeaf21171ce91815bb88991"],"state_sha256":"9547a2cc4cfb9e75f07eba540cbd3f67ea1c49039ded1dae6cc645a9e813d360"}