{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:66TSM5EQZ62ZROGLMKFMBXRVCN","short_pith_number":"pith:66TSM5EQ","canonical_record":{"source":{"id":"2506.01105","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"math.NA","submitted_at":"2025-06-01T18:07:47Z","cross_cats_sorted":["cs.NA","physics.med-ph"],"title_canon_sha256":"ffb6125b2e08df1aa05853466e39dad6ef9d458db7700e1767fc5c64e3111135","abstract_canon_sha256":"c82b146d9339463ac21d10936087a9f555a87295a9489ddbd7d9834f4a5e70b7"},"schema_version":"1.0"},"canonical_sha256":"f7a7267490cfb598b8cb628ac0de351373ae624957845f06eb6c30962716a1a7","source":{"kind":"arxiv","id":"2506.01105","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"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:66TSM5EQZ62ZROGLMKFMBXRVCN","target":"record","payload":{"canonical_record":{"source":{"id":"2506.01105","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"math.NA","submitted_at":"2025-06-01T18:07:47Z","cross_cats_sorted":["cs.NA","physics.med-ph"],"title_canon_sha256":"ffb6125b2e08df1aa05853466e39dad6ef9d458db7700e1767fc5c64e3111135","abstract_canon_sha256":"c82b146d9339463ac21d10936087a9f555a87295a9489ddbd7d9834f4a5e70b7"},"schema_version":"1.0"},"canonical_sha256":"f7a7267490cfb598b8cb628ac0de351373ae624957845f06eb6c30962716a1a7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:13:46.506603Z","signature_b64":"6MxuTjY1Sv3WU1dIpe8dfZws6/2DAhfwxsCTPM6vy11sOkJhC2OGkEhSejx4uJQ9+da6+HZ1VpBQCtv75CNfAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f7a7267490cfb598b8cb628ac0de351373ae624957845f06eb6c30962716a1a7","last_reissued_at":"2026-07-05T11:13:46.506166Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:13:46.506166Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2506.01105","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T11:13:46Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"fI+W0sVv/oXeIWjIVMHoajbl3sp7PLfcKE7O5NhOMkUNyUZ92nhCwx4EoodEf4LeJprfz7Ola9k5qkTLpG94Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T06:39:32.689041Z"},"content_sha256":"001f9d6ea227c65f97ed241cff878dd5e5d7604c043b18e37035923fe24cc4c8","schema_version":"1.0","event_id":"sha256:001f9d6ea227c65f97ed241cff878dd5e5d7604c043b18e37035923fe24cc4c8"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:66TSM5EQZ62ZROGLMKFMBXRVCN","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Positivity-Preserving Finite Element Framework for Accurate Dose Computation in Proton Therapy","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["cs.NA","physics.med-ph"],"primary_cat":"math.NA","authors_text":"Abdalaziz Hamdan, Ben S. Ashby, Tristan Pryer","submitted_at":"2025-06-01T18:07:47Z","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"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2506.01105","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2506.01105/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T11:13:46Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ZnALwiX/keeSUK/sUkFlgpV/k5J5UJE/6w9Ey5rVzFrRzUPTXS+yOd97DZvhguN4XK5UVusI/l+pE4ojhzOqAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T06:39:32.689547Z"},"content_sha256":"fc2ae8e27e289e4134c9ceeae9ffb62fda4c15fc10cd780f1bf02627c742ff71","schema_version":"1.0","event_id":"sha256:fc2ae8e27e289e4134c9ceeae9ffb62fda4c15fc10cd780f1bf02627c742ff71"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/bundle.json","state_url":"https://pith.science/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/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":"2026-08-08T06:39:32Z","links":{"resolver":"https://pith.science/pith/66TSM5EQZ62ZROGLMKFMBXRVCN","bundle":"https://pith.science/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/bundle.json","state":"https://pith.science/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/state.json","well_known_bundle":"https://pith.science/.well-known/pith/66TSM5EQZ62ZROGLMKFMBXRVCN/bundle.json"},"state":{"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"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"olT9I8St+CvISdVTm2kn7jn1o+d9eBuebOc5IOfVZi/lyi3scGsG0iXyG/zSsOktuJO+LXrz8fh+RuSqZ8xmCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-08T06:39:32.694548Z","bundle_sha256":"5a16ef9785796358e3dc3f5563074102465f338f8cb2c50eee9b93e74e11109f"}}