{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:66TSM5EQZ62ZROGLMKFMBXRVCN","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":"c82b146d9339463ac21d10936087a9f555a87295a9489ddbd7d9834f4a5e70b7","cross_cats_sorted":["cs.NA","physics.med-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"math.NA","submitted_at":"2025-06-01T18:07:47Z","title_canon_sha256":"ffb6125b2e08df1aa05853466e39dad6ef9d458db7700e1767fc5c64e3111135"},"schema_version":"1.0","source":{"id":"2506.01105","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2506.01105","created_at":"2026-07-05T11:13:46Z"},{"alias_kind":"arxiv_version","alias_value":"2506.01105v1","created_at":"2026-07-05T11:13:46Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2506.01105","created_at":"2026-07-05T11:13:46Z"},{"alias_kind":"pith_short_12","alias_value":"66TSM5EQZ62Z","created_at":"2026-07-05T11:13:46Z"},{"alias_kind":"pith_short_16","alias_value":"66TSM5EQZ62ZROGL","created_at":"2026-07-05T11:13:46Z"},{"alias_kind":"pith_short_8","alias_value":"66TSM5EQ","created_at":"2026-07-05T11:13:46Z"}],"graph_snapshots":[{"event_id":"sha256:fc2ae8e27e289e4134c9ceeae9ffb62fda4c15fc10cd780f1bf02627c742ff71","target":"graph","created_at":"2026-07-05T11:13:46Z","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/2506.01105/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We present a stabilised finite element method for modelling proton transport in tissue, incorporating both inelastic energy loss and elastic angular scattering. A key innovation is a positivity-preserving formulation that guarantees non-negative fluence and dose, even on coarse meshes. This enables reliable computation of clinically relevant quantities for treatment planning. We derive a priori error estimates demonstrating optimal convergence rates and validate the method through numerical benchmarks. The proposed framework provides a robust, accurate and efficient tool for advancing proton b","authors_text":"Abdalaziz Hamdan, Ben S. Ashby, Tristan Pryer","cross_cats":["cs.NA","physics.med-ph"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"math.NA","submitted_at":"2025-06-01T18:07:47Z","title":"A Positivity-Preserving Finite Element Framework for Accurate Dose Computation in Proton Therapy"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2506.01105","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":"sha256:001f9d6ea227c65f97ed241cff878dd5e5d7604c043b18e37035923fe24cc4c8","target":"record","created_at":"2026-07-05T11:13:46Z","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":"c82b146d9339463ac21d10936087a9f555a87295a9489ddbd7d9834f4a5e70b7","cross_cats_sorted":["cs.NA","physics.med-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"math.NA","submitted_at":"2025-06-01T18:07:47Z","title_canon_sha256":"ffb6125b2e08df1aa05853466e39dad6ef9d458db7700e1767fc5c64e3111135"},"schema_version":"1.0","source":{"id":"2506.01105","kind":"arxiv","version":1}},"canonical_sha256":"f7a7267490cfb598b8cb628ac0de351373ae624957845f06eb6c30962716a1a7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f7a7267490cfb598b8cb628ac0de351373ae624957845f06eb6c30962716a1a7","first_computed_at":"2026-07-05T11:13:46.506166Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:13:46.506166Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"6MxuTjY1Sv3WU1dIpe8dfZws6/2DAhfwxsCTPM6vy11sOkJhC2OGkEhSejx4uJQ9+da6+HZ1VpBQCtv75CNfAA==","signature_status":"signed_v1","signed_at":"2026-07-05T11:13:46.506603Z","signed_message":"canonical_sha256_bytes"},"source_id":"2506.01105","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:001f9d6ea227c65f97ed241cff878dd5e5d7604c043b18e37035923fe24cc4c8","sha256:fc2ae8e27e289e4134c9ceeae9ffb62fda4c15fc10cd780f1bf02627c742ff71"],"state_sha256":"743e6b78aebba94aa1140170e5cb773e54f557e6b4f7747f81368e57fd4f68f2"}