{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:FMOKQ7RSF77CKNG2FFL7SFVUXE","short_pith_number":"pith:FMOKQ7RS","canonical_record":{"source":{"id":"2009.12638","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.MS","submitted_at":"2020-09-26T16:44:34Z","cross_cats_sorted":[],"title_canon_sha256":"e72de247a3b823c92fd1b0bae01821cf35ff0cdef6e16db1ea4802cceab839c5","abstract_canon_sha256":"5fe53e120109309be06ff07699824149f688d47cf92f8ffc12d293e92ef9720d"},"schema_version":"1.0"},"canonical_sha256":"2b1ca87e322ffe2534da2957f916b4b918fbc5aadf3bcf4704c01585a6e9a65a","source":{"kind":"arxiv","id":"2009.12638","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2009.12638","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"arxiv_version","alias_value":"2009.12638v1","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2009.12638","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_12","alias_value":"FMOKQ7RSF77C","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_16","alias_value":"FMOKQ7RSF77CKNG2","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_8","alias_value":"FMOKQ7RS","created_at":"2026-07-05T01:38:21Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:FMOKQ7RSF77CKNG2FFL7SFVUXE","target":"record","payload":{"canonical_record":{"source":{"id":"2009.12638","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.MS","submitted_at":"2020-09-26T16:44:34Z","cross_cats_sorted":[],"title_canon_sha256":"e72de247a3b823c92fd1b0bae01821cf35ff0cdef6e16db1ea4802cceab839c5","abstract_canon_sha256":"5fe53e120109309be06ff07699824149f688d47cf92f8ffc12d293e92ef9720d"},"schema_version":"1.0"},"canonical_sha256":"2b1ca87e322ffe2534da2957f916b4b918fbc5aadf3bcf4704c01585a6e9a65a","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:38:21.990158Z","signature_b64":"D0G2+TOMltiagUzugipFBXdmIDfhsFYej2mj6kT5uRJOs86Mp9nMbe7NGHgdzvnqJ7gC7HxeiafBtIQtQ8YyDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2b1ca87e322ffe2534da2957f916b4b918fbc5aadf3bcf4704c01585a6e9a65a","last_reissued_at":"2026-07-05T01:38:21.989745Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:38:21.989745Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2009.12638","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":"2026-07-05T01:38:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4l9tJ5MhkSTJXU0etzpSpoS9pu2NFzmrMtfV7CiR8PKtAi/ow6E5loKu32vnTAaMAdy5PkO5fXwa6UKbXhKDDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T15:39:02.841634Z"},"content_sha256":"7b8e035dea77c0b5bc20282f38ded7aa048a9bbbe4701d1f06ed8ac3e86c0664","schema_version":"1.0","event_id":"sha256:7b8e035dea77c0b5bc20282f38ded7aa048a9bbbe4701d1f06ed8ac3e86c0664"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:FMOKQ7RSF77CKNG2FFL7SFVUXE","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A highly scalable approach to solving linear systems using two-stage multisplitting","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.MS","authors_text":"Iain Bethune, J. Mark Bull, Nick Brown","submitted_at":"2020-09-26T16:44:34Z","abstract_excerpt":"Iterative methods for solving large sparse systems of linear equations are widely used in many HPC applications. Extreme scaling of these methods can be difficult, however, since global communication to form dot products is typically required at every iteration.\n  To try to overcome this limitation we propose a hybrid approach, where the matrix is partitioned into blocks. Within each block, we use a highly optimised (parallel) conventional solver, but we then couple the blocks together using block Jacobi or some other multisplitting technique that can be implemented in either a synchronous or "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2009.12638","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/2009.12638/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":"2026-07-05T01:38:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"DmnyHFhG1fSJFd6nBlJ9xV8CB6/EJSfVEs5XCKqd0OJm9psHEAjfW/JeSzoHrxa6tbNWCMfQ2erQF937WfRuDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T15:39:02.842133Z"},"content_sha256":"388c93e8b240f5cdc118c4c0d2676f8d1b82153426c524e7b32d519b5c799659","schema_version":"1.0","event_id":"sha256:388c93e8b240f5cdc118c4c0d2676f8d1b82153426c524e7b32d519b5c799659"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/bundle.json","state_url":"https://pith.science/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/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":"2026-08-03T15:39:02Z","links":{"resolver":"https://pith.science/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE","bundle":"https://pith.science/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/bundle.json","state":"https://pith.science/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/state.json","well_known_bundle":"https://pith.science/.well-known/pith/FMOKQ7RSF77CKNG2FFL7SFVUXE/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:FMOKQ7RSF77CKNG2FFL7SFVUXE","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":"5fe53e120109309be06ff07699824149f688d47cf92f8ffc12d293e92ef9720d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.MS","submitted_at":"2020-09-26T16:44:34Z","title_canon_sha256":"e72de247a3b823c92fd1b0bae01821cf35ff0cdef6e16db1ea4802cceab839c5"},"schema_version":"1.0","source":{"id":"2009.12638","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2009.12638","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"arxiv_version","alias_value":"2009.12638v1","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2009.12638","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_12","alias_value":"FMOKQ7RSF77C","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_16","alias_value":"FMOKQ7RSF77CKNG2","created_at":"2026-07-05T01:38:21Z"},{"alias_kind":"pith_short_8","alias_value":"FMOKQ7RS","created_at":"2026-07-05T01:38:21Z"}],"graph_snapshots":[{"event_id":"sha256:388c93e8b240f5cdc118c4c0d2676f8d1b82153426c524e7b32d519b5c799659","target":"graph","created_at":"2026-07-05T01:38:21Z","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/2009.12638/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Iterative methods for solving large sparse systems of linear equations are widely used in many HPC applications. Extreme scaling of these methods can be difficult, however, since global communication to form dot products is typically required at every iteration.\n  To try to overcome this limitation we propose a hybrid approach, where the matrix is partitioned into blocks. Within each block, we use a highly optimised (parallel) conventional solver, but we then couple the blocks together using block Jacobi or some other multisplitting technique that can be implemented in either a synchronous or ","authors_text":"Iain Bethune, J. Mark Bull, Nick Brown","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.MS","submitted_at":"2020-09-26T16:44:34Z","title":"A highly scalable approach to solving linear systems using two-stage multisplitting"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2009.12638","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":"sha256:7b8e035dea77c0b5bc20282f38ded7aa048a9bbbe4701d1f06ed8ac3e86c0664","target":"record","created_at":"2026-07-05T01:38:21Z","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":"5fe53e120109309be06ff07699824149f688d47cf92f8ffc12d293e92ef9720d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.MS","submitted_at":"2020-09-26T16:44:34Z","title_canon_sha256":"e72de247a3b823c92fd1b0bae01821cf35ff0cdef6e16db1ea4802cceab839c5"},"schema_version":"1.0","source":{"id":"2009.12638","kind":"arxiv","version":1}},"canonical_sha256":"2b1ca87e322ffe2534da2957f916b4b918fbc5aadf3bcf4704c01585a6e9a65a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2b1ca87e322ffe2534da2957f916b4b918fbc5aadf3bcf4704c01585a6e9a65a","first_computed_at":"2026-07-05T01:38:21.989745Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:38:21.989745Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"D0G2+TOMltiagUzugipFBXdmIDfhsFYej2mj6kT5uRJOs86Mp9nMbe7NGHgdzvnqJ7gC7HxeiafBtIQtQ8YyDg==","signature_status":"signed_v1","signed_at":"2026-07-05T01:38:21.990158Z","signed_message":"canonical_sha256_bytes"},"source_id":"2009.12638","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7b8e035dea77c0b5bc20282f38ded7aa048a9bbbe4701d1f06ed8ac3e86c0664","sha256:388c93e8b240f5cdc118c4c0d2676f8d1b82153426c524e7b32d519b5c799659"],"state_sha256":"52bdd6923af821c47bb0b913dd056644a8791c56654a572be6a426224559fc2e"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CD6MdLHMH8ZzNHRe+dggwGsqGNuWcbFB73RzsaFOvZWsvORqAWds3heobW5bpCBDcv/D6CzBXSll3c9b6xkuCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-03T15:39:02.845708Z","bundle_sha256":"8703af5309f77564d5fd55701a42cf96aacc6f36e267f588c8dfff1c01c1e2fb"}}