{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:7HVAYQSSAJ2KXFLLWW243SPACO","short_pith_number":"pith:7HVAYQSS","canonical_record":{"source":{"id":"1807.05479","kind":"arxiv","version":8},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-07-15T02:39:50Z","cross_cats_sorted":["astro-ph.CO","gr-qc","physics.comp-ph"],"title_canon_sha256":"c19c8bb5dc1c4351ee8a92ff9c4aee3db807fd8e17d4a0d8d7f2ddcd6c305e3c","abstract_canon_sha256":"6b507106783227f46c177d3fc38f6cc57ffc05588f1860268de16fde823a4622"},"schema_version":"1.0"},"canonical_sha256":"f9ea0c42520274ab956bb5b5cdc9e01389b2f79f4e3994eb41d045b947e3ca29","source":{"kind":"arxiv","id":"1807.05479","version":8},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.05479","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"arxiv_version","alias_value":"1807.05479v8","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.05479","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_12","alias_value":"7HVAYQSSAJ2K","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_16","alias_value":"7HVAYQSSAJ2KXFLL","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_8","alias_value":"7HVAYQSS","created_at":"2026-07-05T02:57:48Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:7HVAYQSSAJ2KXFLLWW243SPACO","target":"record","payload":{"canonical_record":{"source":{"id":"1807.05479","kind":"arxiv","version":8},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-07-15T02:39:50Z","cross_cats_sorted":["astro-ph.CO","gr-qc","physics.comp-ph"],"title_canon_sha256":"c19c8bb5dc1c4351ee8a92ff9c4aee3db807fd8e17d4a0d8d7f2ddcd6c305e3c","abstract_canon_sha256":"6b507106783227f46c177d3fc38f6cc57ffc05588f1860268de16fde823a4622"},"schema_version":"1.0"},"canonical_sha256":"f9ea0c42520274ab956bb5b5cdc9e01389b2f79f4e3994eb41d045b947e3ca29","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:57:48.388233Z","signature_b64":"x47tcSR688NlPJlM1TgBKVO10XP+ZFYzJpWZJe7+29gwYqtMOkDYwnPRSpQ72Ahgy2ppWjjcC0J1IEb7CnCYBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f9ea0c42520274ab956bb5b5cdc9e01389b2f79f4e3994eb41d045b947e3ca29","last_reissued_at":"2026-07-05T02:57:48.387779Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:57:48.387779Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1807.05479","source_version":8,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:57:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"C944a+aqQFnJCRxqA/zsvn2PHxiJpWfOoG53P+JOaZoLoWTSJI5bHW4WzmXFUVWnn4vJ0ATWUJuW+zUkQO42Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:54:04.561227Z"},"content_sha256":"0d905c821b5f2dda32fd00c100c4a098a9ab0ac73b977a3f2e69d27a6283a3d1","schema_version":"1.0","event_id":"sha256:0d905c821b5f2dda32fd00c100c4a098a9ab0ac73b977a3f2e69d27a6283a3d1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:7HVAYQSSAJ2KXFLLWW243SPACO","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The timestep constraint in solving the gravitational wave equations sourced by hydromagnetic turbulence","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","gr-qc","physics.comp-ph"],"primary_cat":"physics.flu-dyn","authors_text":"A. Brandenburg, A. Kosowsky, A. Roper Pol, S. Mandal, T. Kahniashvili","submitted_at":"2018-07-15T02:39:50Z","abstract_excerpt":"Hydromagnetic turbulence produced during phase transitions in the early universe can be a powerful source of stochastic gravitational waves (GWs). GWs can be modelled by the linearised spatial part of the Einstein equations sourced by the Reynolds and Maxwell stresses. We have implemented two different GW solvers into the {\\sc Pencil Code} -- a code which uses a third order timestep and sixth order finite differences. Using direct numerical integration of the GW equations, we study the appearance of a numerical degradation of the GW amplitude at the highest wavenumbers, which depends on the le"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.05479","kind":"arxiv","version":8},"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/1807.05479/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":"2026-07-05T02:57:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Lf4R5a90CWjM+bhGj7udS6TklPWEV6KMCcJ0f4gjdiC/Sc7/TWNtBWQmq4xAHid4XE3qmOW3nMqJwH+kl6MlAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T20:54:04.562035Z"},"content_sha256":"6d7684c62ee02b76570869fedd9483c775de08de41fdcb2ea36b2fc3d7083b68","schema_version":"1.0","event_id":"sha256:6d7684c62ee02b76570869fedd9483c775de08de41fdcb2ea36b2fc3d7083b68"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7HVAYQSSAJ2KXFLLWW243SPACO/bundle.json","state_url":"https://pith.science/pith/7HVAYQSSAJ2KXFLLWW243SPACO/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7HVAYQSSAJ2KXFLLWW243SPACO/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":"2026-08-03T20:54:04Z","links":{"resolver":"https://pith.science/pith/7HVAYQSSAJ2KXFLLWW243SPACO","bundle":"https://pith.science/pith/7HVAYQSSAJ2KXFLLWW243SPACO/bundle.json","state":"https://pith.science/pith/7HVAYQSSAJ2KXFLLWW243SPACO/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7HVAYQSSAJ2KXFLLWW243SPACO/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:7HVAYQSSAJ2KXFLLWW243SPACO","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":"6b507106783227f46c177d3fc38f6cc57ffc05588f1860268de16fde823a4622","cross_cats_sorted":["astro-ph.CO","gr-qc","physics.comp-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-07-15T02:39:50Z","title_canon_sha256":"c19c8bb5dc1c4351ee8a92ff9c4aee3db807fd8e17d4a0d8d7f2ddcd6c305e3c"},"schema_version":"1.0","source":{"id":"1807.05479","kind":"arxiv","version":8}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.05479","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"arxiv_version","alias_value":"1807.05479v8","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.05479","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_12","alias_value":"7HVAYQSSAJ2K","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_16","alias_value":"7HVAYQSSAJ2KXFLL","created_at":"2026-07-05T02:57:48Z"},{"alias_kind":"pith_short_8","alias_value":"7HVAYQSS","created_at":"2026-07-05T02:57:48Z"}],"graph_snapshots":[{"event_id":"sha256:6d7684c62ee02b76570869fedd9483c775de08de41fdcb2ea36b2fc3d7083b68","target":"graph","created_at":"2026-07-05T02:57:48Z","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/1807.05479/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Hydromagnetic turbulence produced during phase transitions in the early universe can be a powerful source of stochastic gravitational waves (GWs). GWs can be modelled by the linearised spatial part of the Einstein equations sourced by the Reynolds and Maxwell stresses. We have implemented two different GW solvers into the {\\sc Pencil Code} -- a code which uses a third order timestep and sixth order finite differences. Using direct numerical integration of the GW equations, we study the appearance of a numerical degradation of the GW amplitude at the highest wavenumbers, which depends on the le","authors_text":"A. Brandenburg, A. Kosowsky, A. Roper Pol, S. Mandal, T. Kahniashvili","cross_cats":["astro-ph.CO","gr-qc","physics.comp-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-07-15T02:39:50Z","title":"The timestep constraint in solving the gravitational wave equations sourced by hydromagnetic turbulence"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.05479","kind":"arxiv","version":8},"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":"sha256:0d905c821b5f2dda32fd00c100c4a098a9ab0ac73b977a3f2e69d27a6283a3d1","target":"record","created_at":"2026-07-05T02:57:48Z","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":"6b507106783227f46c177d3fc38f6cc57ffc05588f1860268de16fde823a4622","cross_cats_sorted":["astro-ph.CO","gr-qc","physics.comp-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2018-07-15T02:39:50Z","title_canon_sha256":"c19c8bb5dc1c4351ee8a92ff9c4aee3db807fd8e17d4a0d8d7f2ddcd6c305e3c"},"schema_version":"1.0","source":{"id":"1807.05479","kind":"arxiv","version":8}},"canonical_sha256":"f9ea0c42520274ab956bb5b5cdc9e01389b2f79f4e3994eb41d045b947e3ca29","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f9ea0c42520274ab956bb5b5cdc9e01389b2f79f4e3994eb41d045b947e3ca29","first_computed_at":"2026-07-05T02:57:48.387779Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:57:48.387779Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"x47tcSR688NlPJlM1TgBKVO10XP+ZFYzJpWZJe7+29gwYqtMOkDYwnPRSpQ72Ahgy2ppWjjcC0J1IEb7CnCYBg==","signature_status":"signed_v1","signed_at":"2026-07-05T02:57:48.388233Z","signed_message":"canonical_sha256_bytes"},"source_id":"1807.05479","source_kind":"arxiv","source_version":8}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0d905c821b5f2dda32fd00c100c4a098a9ab0ac73b977a3f2e69d27a6283a3d1","sha256:6d7684c62ee02b76570869fedd9483c775de08de41fdcb2ea36b2fc3d7083b68"],"state_sha256":"b12e3be3f3694c307be390f33767c983848c7c5d3145d99948bea534e149334b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Oi3xudtg2SKy2w9leQSeORF+N3Vy1q6z4L3OMz/q9s84j77K1XOKxQHvhf6VxyaWddypXi3uC57D7xKHSWpkDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-03T20:54:04.567198Z","bundle_sha256":"2348fbeb6707794b3a3d8a8bf43a5df3befaa5b94e075d06750928e4429effcf"}}