{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:MSO3FIJPUX2V4H62AQYULB742A","short_pith_number":"pith:MSO3FIJP","canonical_record":{"source":{"id":"1405.6297","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2014-05-24T12:39:07Z","cross_cats_sorted":[],"title_canon_sha256":"34f90c62b6cd19380e9a3b0b68fa53b273517faddd6019ca3958990c547b065e","abstract_canon_sha256":"eaf598875698743be43df9c0021025bd6bdd1013dfea7e2e16a7156a5e85c93c"},"schema_version":"1.0"},"canonical_sha256":"649db2a12fa5f55e1fda04314587fcd03ec480dcda7dff35b20a99906b694ba1","source":{"kind":"arxiv","id":"1405.6297","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.6297","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"arxiv_version","alias_value":"1405.6297v3","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.6297","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"pith_short_12","alias_value":"MSO3FIJPUX2V","created_at":"2026-05-18T12:28:38Z"},{"alias_kind":"pith_short_16","alias_value":"MSO3FIJPUX2V4H62","created_at":"2026-05-18T12:28:38Z"},{"alias_kind":"pith_short_8","alias_value":"MSO3FIJP","created_at":"2026-05-18T12:28:38Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:MSO3FIJPUX2V4H62AQYULB742A","target":"record","payload":{"canonical_record":{"source":{"id":"1405.6297","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2014-05-24T12:39:07Z","cross_cats_sorted":[],"title_canon_sha256":"34f90c62b6cd19380e9a3b0b68fa53b273517faddd6019ca3958990c547b065e","abstract_canon_sha256":"eaf598875698743be43df9c0021025bd6bdd1013dfea7e2e16a7156a5e85c93c"},"schema_version":"1.0"},"canonical_sha256":"649db2a12fa5f55e1fda04314587fcd03ec480dcda7dff35b20a99906b694ba1","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:17:05.680295Z","signature_b64":"w3NDUfT1HLmivy3GSNpGgzkocRn+SWYacoO5h6emWEz1YE83eE6YVmr+6Uwgey3z1Zd32Nu46SJGU0Z+l2M8DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"649db2a12fa5f55e1fda04314587fcd03ec480dcda7dff35b20a99906b694ba1","last_reissued_at":"2026-05-18T01:17:05.679541Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:17:05.679541Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1405.6297","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:17:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"IWTkc3jJVTS/Z/KhdfBlvI2h8uQSvtj8Cp6w97B2+QX2AwrjvufCf5sTCre7u4rZkloRVLAek9wXnFqtGhWhDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-20T17:44:39.917733Z"},"content_sha256":"5c283f8894c4d5a86c2ac91f69cd0ec40a1c24800fb2e185b517aacdc7d3a6f9","schema_version":"1.0","event_id":"sha256:5c283f8894c4d5a86c2ac91f69cd0ec40a1c24800fb2e185b517aacdc7d3a6f9"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:MSO3FIJPUX2V4H62AQYULB742A","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Preconditioning complex symmetric linear systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.NA","authors_text":"Enrico Bertolazzi, Marco Frego","submitted_at":"2014-05-24T12:39:07Z","abstract_excerpt":"A new polynomial preconditioner for symmetric complex linear systems based on Hermitian and skew-Hermitian splitting (HSS) for complex symmetric linear systems is herein presented. It applies to Conjugate Orthogonal Conjugate Gradient (COCG) or Conjugate Orthogonal Conjugate Residual (COCR) iterative solvers and does not require any estimation of the spectrum of the coefficient matrix. An upper bound of the condition number of the preconditioned linear system is provided. Moreover, to reduce the computational cost, an inexact variant based on incomplete Cholesky decomposition or orthogonal pol"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.6297","kind":"arxiv","version":3},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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":"2026-05-18T01:17:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/mJQDfWBOfBA4ByG+2Pkt72p5GQaEg9Jmp2mHV2c4xZCVzVjBg0NIm+rWKSBI0qbecAZ+JCe0badWRDBIb14Bw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-20T17:44:39.918069Z"},"content_sha256":"198f929f69ebf43b9555ee3d8bb069254a3ff96beed670cd80cd8434064cf8cb","schema_version":"1.0","event_id":"sha256:198f929f69ebf43b9555ee3d8bb069254a3ff96beed670cd80cd8434064cf8cb"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MSO3FIJPUX2V4H62AQYULB742A/bundle.json","state_url":"https://pith.science/pith/MSO3FIJPUX2V4H62AQYULB742A/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MSO3FIJPUX2V4H62AQYULB742A/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":"2026-06-20T17:44:39Z","links":{"resolver":"https://pith.science/pith/MSO3FIJPUX2V4H62AQYULB742A","bundle":"https://pith.science/pith/MSO3FIJPUX2V4H62AQYULB742A/bundle.json","state":"https://pith.science/pith/MSO3FIJPUX2V4H62AQYULB742A/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MSO3FIJPUX2V4H62AQYULB742A/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:MSO3FIJPUX2V4H62AQYULB742A","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":"eaf598875698743be43df9c0021025bd6bdd1013dfea7e2e16a7156a5e85c93c","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2014-05-24T12:39:07Z","title_canon_sha256":"34f90c62b6cd19380e9a3b0b68fa53b273517faddd6019ca3958990c547b065e"},"schema_version":"1.0","source":{"id":"1405.6297","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.6297","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"arxiv_version","alias_value":"1405.6297v3","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.6297","created_at":"2026-05-18T01:17:05Z"},{"alias_kind":"pith_short_12","alias_value":"MSO3FIJPUX2V","created_at":"2026-05-18T12:28:38Z"},{"alias_kind":"pith_short_16","alias_value":"MSO3FIJPUX2V4H62","created_at":"2026-05-18T12:28:38Z"},{"alias_kind":"pith_short_8","alias_value":"MSO3FIJP","created_at":"2026-05-18T12:28:38Z"}],"graph_snapshots":[{"event_id":"sha256:198f929f69ebf43b9555ee3d8bb069254a3ff96beed670cd80cd8434064cf8cb","target":"graph","created_at":"2026-05-18T01:17:05Z","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"},"paper":{"abstract_excerpt":"A new polynomial preconditioner for symmetric complex linear systems based on Hermitian and skew-Hermitian splitting (HSS) for complex symmetric linear systems is herein presented. It applies to Conjugate Orthogonal Conjugate Gradient (COCG) or Conjugate Orthogonal Conjugate Residual (COCR) iterative solvers and does not require any estimation of the spectrum of the coefficient matrix. An upper bound of the condition number of the preconditioned linear system is provided. Moreover, to reduce the computational cost, an inexact variant based on incomplete Cholesky decomposition or orthogonal pol","authors_text":"Enrico Bertolazzi, Marco Frego","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2014-05-24T12:39:07Z","title":"Preconditioning complex symmetric linear systems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.6297","kind":"arxiv","version":3},"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":"sha256:5c283f8894c4d5a86c2ac91f69cd0ec40a1c24800fb2e185b517aacdc7d3a6f9","target":"record","created_at":"2026-05-18T01:17:05Z","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":"eaf598875698743be43df9c0021025bd6bdd1013dfea7e2e16a7156a5e85c93c","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2014-05-24T12:39:07Z","title_canon_sha256":"34f90c62b6cd19380e9a3b0b68fa53b273517faddd6019ca3958990c547b065e"},"schema_version":"1.0","source":{"id":"1405.6297","kind":"arxiv","version":3}},"canonical_sha256":"649db2a12fa5f55e1fda04314587fcd03ec480dcda7dff35b20a99906b694ba1","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"649db2a12fa5f55e1fda04314587fcd03ec480dcda7dff35b20a99906b694ba1","first_computed_at":"2026-05-18T01:17:05.679541Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:17:05.679541Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"w3NDUfT1HLmivy3GSNpGgzkocRn+SWYacoO5h6emWEz1YE83eE6YVmr+6Uwgey3z1Zd32Nu46SJGU0Z+l2M8DA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:17:05.680295Z","signed_message":"canonical_sha256_bytes"},"source_id":"1405.6297","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5c283f8894c4d5a86c2ac91f69cd0ec40a1c24800fb2e185b517aacdc7d3a6f9","sha256:198f929f69ebf43b9555ee3d8bb069254a3ff96beed670cd80cd8434064cf8cb"],"state_sha256":"da9d00490c749dc98801ac9c2cf8d59c9e2c2379eef473d50bdcb288fa07e8fd"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"po2MsXeYaBCwukyfRzdepEFsJM1Z5iOwwCgnf1Sge+z0CZ+UaolfW18AgLA147FTMySJdzOYyH7G+JLVHjlXAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-20T17:44:39.919947Z","bundle_sha256":"78c724ffb11083b291bbcb5e517092f24f451000f11ead3f256d4b072d0201cb"}}