{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","short_pith_number":"pith:ZB44UIIB","canonical_record":{"source":{"id":"2607.06429","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2026-07-07T15:55:49Z","cross_cats_sorted":["cs.NA","physics.comp-ph"],"title_canon_sha256":"05b448d3bf98017ebb745ba53fea047fe1554f607a22e979a609d509bf0dbee7","abstract_canon_sha256":"7c86f41ce14601826242e7077190556c1a7b6ab86ffa8fa0e54115b057a0811f"},"schema_version":"1.0"},"canonical_sha256":"c879ca2101ba1b66dc698ea551e6a95111a6413b38e46aa99ede561499e0aae6","source":{"kind":"arxiv","id":"2607.06429","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2607.06429","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"arxiv_version","alias_value":"2607.06429v1","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2607.06429","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_12","alias_value":"ZB44UIIBXINW","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_16","alias_value":"ZB44UIIBXINWNXDJ","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_8","alias_value":"ZB44UIIB","created_at":"2026-07-08T01:19:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","target":"record","payload":{"canonical_record":{"source":{"id":"2607.06429","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2026-07-07T15:55:49Z","cross_cats_sorted":["cs.NA","physics.comp-ph"],"title_canon_sha256":"05b448d3bf98017ebb745ba53fea047fe1554f607a22e979a609d509bf0dbee7","abstract_canon_sha256":"7c86f41ce14601826242e7077190556c1a7b6ab86ffa8fa0e54115b057a0811f"},"schema_version":"1.0"},"canonical_sha256":"c879ca2101ba1b66dc698ea551e6a95111a6413b38e46aa99ede561499e0aae6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-08T01:19:25.034459Z","signature_b64":"ZSTQ5nw42/COS3BWrSCFkeVx6bIfyDrSUK5jrK8+ERWiqJT3T28UMwxbQWqnBCfJ5u/wrvw+nxtw3EIFklOoCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c879ca2101ba1b66dc698ea551e6a95111a6413b38e46aa99ede561499e0aae6","last_reissued_at":"2026-07-08T01:19:25.033892Z","signature_status":"signed_v1","first_computed_at":"2026-07-08T01:19:25.033892Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2607.06429","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":"2026-07-08T01:19:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"y3Dg+0LDI1mKC3JZpUF07LIt8n9+jVsZ8WvFsMHOjHSDDAcXDW/Hj2MmZEe89fY9/nVhf1Tz8sKAt1Xqi/6fAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:49:19.974385Z"},"content_sha256":"c8464ace5c32a5147174d631904bfb7d42791305525e1a3b80c183c698285c43","schema_version":"1.0","event_id":"sha256:c8464ace5c32a5147174d631904bfb7d42791305525e1a3b80c183c698285c43"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Nested Volume-Surface Integral Equations for Acoustics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.NA","physics.comp-ph"],"primary_cat":"math.NA","authors_text":"Danilo Aballay, Elwin van 't Wout","submitted_at":"2026-07-07T15:55:49Z","abstract_excerpt":"The simulation of high-frequency acoustic wave propagation in unbounded domains with local heterogeneous materials and high-contrast interfaces poses significant challenges to numerical methods. The volume-surface integral equation (VSIE) method is an attractive approach as it automatically satisfies the radiation condition at infinity via Green's functions, handles heterogeneous materials via Newton potentials, and models scattering at high-contrast interfaces via surface integral operators. However, its effectiveness in practical simulations has been limited by high computational costs, sens"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.06429","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/2607.06429/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":"2026-07-08T01:19:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ySWp8Sa7n7hspihdpxEQ2UAQ0TbeWVjgtGB9Rwd+wYvHrlaj//G52hoLuyhqTqYm8t1qcA21QVenhe/mUezACg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:49:19.974998Z"},"content_sha256":"307bd1c8602691512d206c8de4e17a3901accd6cf1831dcbb3006c126afcbc2f","schema_version":"1.0","event_id":"sha256:307bd1c8602691512d206c8de4e17a3901accd6cf1831dcbb3006c126afcbc2f"},{"event_type":"integrity_finding","subject_pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","target":"integrity","payload":{"note":"Identifier '10.1007/978-3-319-16727-511' is syntactically valid but the DOI registry (doi.org) returned 404, and Crossref / OpenAlex / internal corpus also have no record. The cited work could not be located through any authoritative source.","snippet":"Martin Costabel. On the spectrum of volume integral operators in acoustic scattering. InIntegral Methods in Science and Engineering, pages 119–127. Birkh¨ auser, Cham, 2015. doi:10.1007/978-3-319-16727-511","arxiv_id":"2607.06429","detector":"doi_compliance","evidence":{"doi":"10.1007/978-3-319-16727-511","arxiv_id":null,"ref_index":39,"raw_excerpt":"Martin Costabel. On the spectrum of volume integral operators in acoustic scattering. InIntegral Methods in Science and Engineering, pages 119–127. Birkh¨ auser, Cham, 2015. doi:10.1007/978-3-319-16727-511","verdict_class":"cross_source","checked_sources":["crossref_by_doi","openalex_by_doi","doi_org_head"]},"severity":"critical","ref_index":39,"audited_at":"2026-07-09T07:27:38.807937Z","event_type":"pith.integrity.v1","detected_doi":"10.1007/978-3-319-16727-511","detector_url":"https://pith.science/pith-integrity-protocol#doi_compliance","external_url":null,"finding_type":"unresolvable_identifier","evidence_hash":"d093792340207988dd101fa03f57c75a43c1dd5c7844a605630578807eafc83e","paper_version":1,"verdict_class":"cross_source","resolved_title":null,"detector_version":"1.0.0","detected_arxiv_id":null,"integrity_event_id":7778,"payload_sha256":"de6c44c43b17ac2ef543212ca31eeb554cf4284518782b657bda70676120ec8d","signature_b64":"d4jg2ezIREm+CzXzMBfRhmbsq9UGCe+/WQ1LmURF3enJ0Al3GwrI4eJEdB1wZSIiC7yNy+SygShG74OQerNlBA==","signing_key_id":"pith-v1-2026-05"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-09T07:32:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qY4RxS84yubfnPZWNCDiP0kjRHlfLrukokbgf/PJ+ndGlbiDkM8G9s4kvI4+13u97blEOlABwXIhvU8vw69mDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:49:20.026480Z"},"content_sha256":"b1f6d881b8ef0c176d5690cc64256630aa2c08db5ddfba710d3bc8e252b13460","schema_version":"1.0","event_id":"sha256:b1f6d881b8ef0c176d5690cc64256630aa2c08db5ddfba710d3bc8e252b13460"},{"event_type":"integrity_finding","subject_pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","target":"integrity","payload":{"note":"DOI in the printed bibliography is fragmented by whitespace or line breaks. A longer candidate (10.1007/s10665-008-9218-2.31) was visible in the surrounding text but could not be confirmed against doi.org as printed.","snippet":"MC van Beurden and SJL van Eijndhoven. Well-posedness of domain inte- gral equations for a dielectric object in homogeneous background.Journal of Engineering Mathematics, 62(3):289–302, 2008. doi:10.1007/s10665-008- 9218-2. 31 Aballay and V","arxiv_id":"2607.06429","detector":"doi_compliance","evidence":{"ref_index":24,"verdict_class":"incontrovertible","resolved_title":null,"printed_excerpt":"MC van Beurden and SJL van Eijndhoven. Well-posedness of domain inte- gral equations for a dielectric object in homogeneous background.Journal of Engineering Mathematics, 62(3):289–302, 2008. doi:10.1007/s10665-008- 9218-2. 31 Aballay and V","reconstructed_doi":"10.1007/s10665-008-9218-2.31"},"severity":"advisory","ref_index":24,"audited_at":"2026-07-09T07:27:38.807937Z","event_type":"pith.integrity.v1","detected_doi":"10.1007/s10665-008-9218-2.31","detector_url":"https://pith.science/pith-integrity-protocol#doi_compliance","external_url":null,"finding_type":"recoverable_identifier","evidence_hash":"6d3ca15a7dcc558f7fc871da42bacbc14d598a7a8eb48b8b81492a8cac30ccab","paper_version":1,"verdict_class":"incontrovertible","resolved_title":null,"detector_version":"1.0.0","detected_arxiv_id":null,"integrity_event_id":7777,"payload_sha256":"6c850d15783a685031e06365ea8fb83b9c505cf796ff882bbf3a2ab7132318e2","signature_b64":"d/TQ9hA1P9QaKrCwZeu5OSJUTu6DgoQ0xI/v7cacss5nj/k7/LTaXqv3flEK46mnadxvI9CrY0gk+mFbGy2MBQ==","signing_key_id":"pith-v1-2026-05"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-09T07:32:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SLsE9hdUWnPUtt3OUefpwcX/0Ei+muV/dkAKvX0QCnErFfNm/VenetPOeIklVNTs8zhTF1ovCeudzdUuStPtAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:49:20.027466Z"},"content_sha256":"c10eaa42771f2bc48c3c89a4b123eb9ec458b1a910e04053a09312231690db94","schema_version":"1.0","event_id":"sha256:c10eaa42771f2bc48c3c89a4b123eb9ec458b1a910e04053a09312231690db94"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/bundle.json","state_url":"https://pith.science/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/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":"2026-08-03T20:49:20Z","links":{"resolver":"https://pith.science/pith/ZB44UIIBXINWNXDJR2SVDZVJKE","bundle":"https://pith.science/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/bundle.json","state":"https://pith.science/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ZB44UIIBXINWNXDJR2SVDZVJKE/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:ZB44UIIBXINWNXDJR2SVDZVJKE","merge_version":"pith-open-graph-merge-v1","event_count":4,"valid_event_count":4,"invalid_event_count":0,"equivocation_count":1,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"7c86f41ce14601826242e7077190556c1a7b6ab86ffa8fa0e54115b057a0811f","cross_cats_sorted":["cs.NA","physics.comp-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2026-07-07T15:55:49Z","title_canon_sha256":"05b448d3bf98017ebb745ba53fea047fe1554f607a22e979a609d509bf0dbee7"},"schema_version":"1.0","source":{"id":"2607.06429","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2607.06429","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"arxiv_version","alias_value":"2607.06429v1","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2607.06429","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_12","alias_value":"ZB44UIIBXINW","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_16","alias_value":"ZB44UIIBXINWNXDJ","created_at":"2026-07-08T01:19:25Z"},{"alias_kind":"pith_short_8","alias_value":"ZB44UIIB","created_at":"2026-07-08T01:19:25Z"}],"graph_snapshots":[{"event_id":"sha256:307bd1c8602691512d206c8de4e17a3901accd6cf1831dcbb3006c126afcbc2f","target":"graph","created_at":"2026-07-08T01:19:25Z","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/2607.06429/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The simulation of high-frequency acoustic wave propagation in unbounded domains with local heterogeneous materials and high-contrast interfaces poses significant challenges to numerical methods. The volume-surface integral equation (VSIE) method is an attractive approach as it automatically satisfies the radiation condition at infinity via Green's functions, handles heterogeneous materials via Newton potentials, and models scattering at high-contrast interfaces via surface integral operators. However, its effectiveness in practical simulations has been limited by high computational costs, sens","authors_text":"Danilo Aballay, Elwin van 't Wout","cross_cats":["cs.NA","physics.comp-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2026-07-07T15:55:49Z","title":"Nested Volume-Surface Integral Equations for Acoustics"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.06429","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:c8464ace5c32a5147174d631904bfb7d42791305525e1a3b80c183c698285c43","target":"record","created_at":"2026-07-08T01:19:25Z","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":"7c86f41ce14601826242e7077190556c1a7b6ab86ffa8fa0e54115b057a0811f","cross_cats_sorted":["cs.NA","physics.comp-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2026-07-07T15:55:49Z","title_canon_sha256":"05b448d3bf98017ebb745ba53fea047fe1554f607a22e979a609d509bf0dbee7"},"schema_version":"1.0","source":{"id":"2607.06429","kind":"arxiv","version":1}},"canonical_sha256":"c879ca2101ba1b66dc698ea551e6a95111a6413b38e46aa99ede561499e0aae6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c879ca2101ba1b66dc698ea551e6a95111a6413b38e46aa99ede561499e0aae6","first_computed_at":"2026-07-08T01:19:25.033892Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-08T01:19:25.033892Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ZSTQ5nw42/COS3BWrSCFkeVx6bIfyDrSUK5jrK8+ERWiqJT3T28UMwxbQWqnBCfJ5u/wrvw+nxtw3EIFklOoCA==","signature_status":"signed_v1","signed_at":"2026-07-08T01:19:25.034459Z","signed_message":"canonical_sha256_bytes"},"source_id":"2607.06429","source_kind":"arxiv","source_version":1}}},"equivocations":[{"signer_id":"pith.science","event_type":"integrity_finding","target":"integrity","event_ids":["sha256:b1f6d881b8ef0c176d5690cc64256630aa2c08db5ddfba710d3bc8e252b13460","sha256:c10eaa42771f2bc48c3c89a4b123eb9ec458b1a910e04053a09312231690db94"]}],"invalid_events":[],"applied_event_ids":["sha256:c8464ace5c32a5147174d631904bfb7d42791305525e1a3b80c183c698285c43","sha256:307bd1c8602691512d206c8de4e17a3901accd6cf1831dcbb3006c126afcbc2f"],"state_sha256":"54c907121f7dcc8ac2f372320b6a61ff614c12ae5855c9c9a12a4da596ca4f23"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"nxY3HUapCaiQNQDPp56LYhstUYGYagr7XigybLRUqD9cvVyqwogG16CKEkSkRQO5fA2lN6PinvpwGqiGCkRNDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-03T20:49:20.031236Z","bundle_sha256":"1a11c45d4a783fbee5f9bfb8c0a57a220f5f7399fc78786970991d1372902cc5"}}