{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:45MCUX27YHRPANMTNGZBDLMWGB","short_pith_number":"pith:45MCUX27","canonical_record":{"source":{"id":"2008.04772","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2020-08-11T15:23:16Z","cross_cats_sorted":["cs.NA"],"title_canon_sha256":"14bd4303d82361ccc20c8cf35355b82b5263e5d30a8230544c8a71b4a6c9a16a","abstract_canon_sha256":"fcbdf6d93e487e7f38e176b2625ed6a54efb24ed54c18a82e43d52c9d5549527"},"schema_version":"1.0"},"canonical_sha256":"e7582a5f5fc1e2f0359369b211ad96307f6d53b7541bab2a39413a24d10da966","source":{"kind":"arxiv","id":"2008.04772","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2008.04772","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"arxiv_version","alias_value":"2008.04772v2","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2008.04772","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_12","alias_value":"45MCUX27YHRP","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_16","alias_value":"45MCUX27YHRPANMT","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_8","alias_value":"45MCUX27","created_at":"2026-07-05T04:01:20Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:45MCUX27YHRPANMTNGZBDLMWGB","target":"record","payload":{"canonical_record":{"source":{"id":"2008.04772","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2020-08-11T15:23:16Z","cross_cats_sorted":["cs.NA"],"title_canon_sha256":"14bd4303d82361ccc20c8cf35355b82b5263e5d30a8230544c8a71b4a6c9a16a","abstract_canon_sha256":"fcbdf6d93e487e7f38e176b2625ed6a54efb24ed54c18a82e43d52c9d5549527"},"schema_version":"1.0"},"canonical_sha256":"e7582a5f5fc1e2f0359369b211ad96307f6d53b7541bab2a39413a24d10da966","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T04:01:20.706173Z","signature_b64":"ZeUgrJq3k5xun/13gfGOsya8GQvEQSdu7YpvKJlfWn2CS80/YjZC5KyvBSJvX79EADzQ/2RwC/QVzi+NsvGwAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e7582a5f5fc1e2f0359369b211ad96307f6d53b7541bab2a39413a24d10da966","last_reissued_at":"2026-07-05T04:01:20.705750Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T04:01:20.705750Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2008.04772","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T04:01:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"u7rjyZhu1FPq+kdNVmt9gxb+IxHQKh4I6fWiXFMoJYgWJhr9pB4xSM5Imufyl4yaDxbTVbZchKsMOrgAri0mBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-13T12:07:10.202156Z"},"content_sha256":"332729abc687c101cc1e454dabb61cc6cbfa3a4250bb78e37cc2101fe302f285","schema_version":"1.0","event_id":"sha256:332729abc687c101cc1e454dabb61cc6cbfa3a4250bb78e37cc2101fe302f285"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:45MCUX27YHRPANMTNGZBDLMWGB","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Accelerated Calder\\'on preconditioning for Maxwell transmission problems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.NA"],"primary_cat":"math.NA","authors_text":"Anthony J. Baran, Antigoni Kleanthous, Carlos Jerez-Hanckes, David P. Hewett, Paul Escapil-Inchausp\\'e, Timo Betcke","submitted_at":"2020-08-11T15:23:16Z","abstract_excerpt":"We investigate a range of techniques for the acceleration of Calder\\'on (operator) preconditioning in the context of boundary integral equation methods for electromagnetic transmission problems. Our objective is to mitigate as far as possible the high computational cost of the barycentrically-refined meshes necessary for the stable discretisation of operator products. Our focus is on the well-known PMCHWT formulation, but the techniques we introduce can be applied generically. By using barycentric meshes only for the preconditioner and not for the original boundary integral operator, we achiev"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.04772","kind":"arxiv","version":2},"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/2008.04772/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":"2026-07-05T04:01:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"N2TCpo97memKn8cBi5thni1a8i1PJgU57rYGmWWjOnsG/UcD315k/vio16JxaLGOL8q9UpQJgiHjVUNds2efCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-13T12:07:10.202749Z"},"content_sha256":"e6840c703bd6d25ddeb5303d72412f199eda1eb16445616bb994632f3620cfcf","schema_version":"1.0","event_id":"sha256:e6840c703bd6d25ddeb5303d72412f199eda1eb16445616bb994632f3620cfcf"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/45MCUX27YHRPANMTNGZBDLMWGB/bundle.json","state_url":"https://pith.science/pith/45MCUX27YHRPANMTNGZBDLMWGB/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/45MCUX27YHRPANMTNGZBDLMWGB/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":"2026-08-13T12:07:10Z","links":{"resolver":"https://pith.science/pith/45MCUX27YHRPANMTNGZBDLMWGB","bundle":"https://pith.science/pith/45MCUX27YHRPANMTNGZBDLMWGB/bundle.json","state":"https://pith.science/pith/45MCUX27YHRPANMTNGZBDLMWGB/state.json","well_known_bundle":"https://pith.science/.well-known/pith/45MCUX27YHRPANMTNGZBDLMWGB/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:45MCUX27YHRPANMTNGZBDLMWGB","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":"fcbdf6d93e487e7f38e176b2625ed6a54efb24ed54c18a82e43d52c9d5549527","cross_cats_sorted":["cs.NA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2020-08-11T15:23:16Z","title_canon_sha256":"14bd4303d82361ccc20c8cf35355b82b5263e5d30a8230544c8a71b4a6c9a16a"},"schema_version":"1.0","source":{"id":"2008.04772","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2008.04772","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"arxiv_version","alias_value":"2008.04772v2","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2008.04772","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_12","alias_value":"45MCUX27YHRP","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_16","alias_value":"45MCUX27YHRPANMT","created_at":"2026-07-05T04:01:20Z"},{"alias_kind":"pith_short_8","alias_value":"45MCUX27","created_at":"2026-07-05T04:01:20Z"}],"graph_snapshots":[{"event_id":"sha256:e6840c703bd6d25ddeb5303d72412f199eda1eb16445616bb994632f3620cfcf","target":"graph","created_at":"2026-07-05T04:01:20Z","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/2008.04772/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We investigate a range of techniques for the acceleration of Calder\\'on (operator) preconditioning in the context of boundary integral equation methods for electromagnetic transmission problems. Our objective is to mitigate as far as possible the high computational cost of the barycentrically-refined meshes necessary for the stable discretisation of operator products. Our focus is on the well-known PMCHWT formulation, but the techniques we introduce can be applied generically. By using barycentric meshes only for the preconditioner and not for the original boundary integral operator, we achiev","authors_text":"Anthony J. Baran, Antigoni Kleanthous, Carlos Jerez-Hanckes, David P. Hewett, Paul Escapil-Inchausp\\'e, Timo Betcke","cross_cats":["cs.NA"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2020-08-11T15:23:16Z","title":"Accelerated Calder\\'on preconditioning for Maxwell transmission problems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.04772","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":"sha256:332729abc687c101cc1e454dabb61cc6cbfa3a4250bb78e37cc2101fe302f285","target":"record","created_at":"2026-07-05T04:01:20Z","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":"fcbdf6d93e487e7f38e176b2625ed6a54efb24ed54c18a82e43d52c9d5549527","cross_cats_sorted":["cs.NA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2020-08-11T15:23:16Z","title_canon_sha256":"14bd4303d82361ccc20c8cf35355b82b5263e5d30a8230544c8a71b4a6c9a16a"},"schema_version":"1.0","source":{"id":"2008.04772","kind":"arxiv","version":2}},"canonical_sha256":"e7582a5f5fc1e2f0359369b211ad96307f6d53b7541bab2a39413a24d10da966","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e7582a5f5fc1e2f0359369b211ad96307f6d53b7541bab2a39413a24d10da966","first_computed_at":"2026-07-05T04:01:20.705750Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T04:01:20.705750Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ZeUgrJq3k5xun/13gfGOsya8GQvEQSdu7YpvKJlfWn2CS80/YjZC5KyvBSJvX79EADzQ/2RwC/QVzi+NsvGwAw==","signature_status":"signed_v1","signed_at":"2026-07-05T04:01:20.706173Z","signed_message":"canonical_sha256_bytes"},"source_id":"2008.04772","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:332729abc687c101cc1e454dabb61cc6cbfa3a4250bb78e37cc2101fe302f285","sha256:e6840c703bd6d25ddeb5303d72412f199eda1eb16445616bb994632f3620cfcf"],"state_sha256":"0a6714329c5fc4af8d3c62e42e45e99e246507d9c1e77a1a408f9fbf62efd059"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"K6cMoX3zKh1xpJKH2AXUj/IHdQz8WbaWUZEA2lJB4QSIPvIdF8gdQnKMIMxkm1TKkn6GdDqD5EOdAz/9GPwGCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-13T12:07:10.207512Z","bundle_sha256":"4aca62be7137dde972308bb110e80183283b64e1cea0861d4727e4e4d03772b8"}}