{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2000:K4Q42LAP2WSDGFS4OVHTXBM7RR","short_pith_number":"pith:K4Q42LAP","schema_version":"1.0","canonical_sha256":"5721cd2c0fd5a433165c754f3b859f8c7497f9e9f959c56dbcd9709da98568a0","source":{"kind":"arxiv","id":"astro-ph/0011548","version":2},"attestation_state":"computed","paper":{"title":"Conservation of Magnetic Helicity and Its Constraint on $\\alpha$-Effect of Dynamo Theory","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"George B. Field, Hongsong Chou","submitted_at":"2000-11-29T17:28:23Z","abstract_excerpt":"Dynamical studies of MHD turbulence on the one hand, and arguments based upon magnetic helicity on the other, have yielded seemingly contradictory estimates for the $\\alpha$ parameter in turbulent dynamo theory. Here we show, with direct numerical simulation of three-dimensional magnetohydrodynamic turbulence with a mean magnetic field, $\\OB$, that the constraint on the dynamo $\\alpha$-effect set by the magnetic helicity is time-dependent. A time-scale $t_c$ is introduced such that for $t<t_c$, the $\\alpha$-coefficient calculated from the simulation is close to the result of Pouquet et al and "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"astro-ph/0011548","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2000-11-29T17:28:23Z","cross_cats_sorted":[],"title_canon_sha256":"18518e12b14399a550bf29ac9deddf8315c62685038cb7965777f1de0146a2c3","abstract_canon_sha256":"712d424ba06a0fd16ea131a8e41914e0b4f46e5397b36ea82ddeff7c8760b033"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T14:10:54.779521Z","signature_b64":"/T7uWD/FClhzhU3hYjPrFxYl5AioTD39x4kr1oTgOUxutafcHyoBk8w+80PLom9Xi/kvTOvjt0ZCr7x+3RVsBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"5721cd2c0fd5a433165c754f3b859f8c7497f9e9f959c56dbcd9709da98568a0","last_reissued_at":"2026-07-04T14:10:54.779169Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T14:10:54.779169Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Conservation of Magnetic Helicity and Its Constraint on $\\alpha$-Effect of Dynamo Theory","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"George B. Field, Hongsong Chou","submitted_at":"2000-11-29T17:28:23Z","abstract_excerpt":"Dynamical studies of MHD turbulence on the one hand, and arguments based upon magnetic helicity on the other, have yielded seemingly contradictory estimates for the $\\alpha$ parameter in turbulent dynamo theory. Here we show, with direct numerical simulation of three-dimensional magnetohydrodynamic turbulence with a mean magnetic field, $\\OB$, that the constraint on the dynamo $\\alpha$-effect set by the magnetic helicity is time-dependent. A time-scale $t_c$ is introduced such that for $t<t_c$, the $\\alpha$-coefficient calculated from the simulation is close to the result of Pouquet et al and "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0011548","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/astro-ph/0011548/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0011548","created_at":"2026-07-04T14:10:54.779224+00:00"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0011548v2","created_at":"2026-07-04T14:10:54.779224+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0011548","created_at":"2026-07-04T14:10:54.779224+00:00"},{"alias_kind":"pith_short_12","alias_value":"K4Q42LAP2WSD","created_at":"2026-07-04T14:10:54.779224+00:00"},{"alias_kind":"pith_short_16","alias_value":"K4Q42LAP2WSDGFS4","created_at":"2026-07-04T14:10:54.779224+00:00"},{"alias_kind":"pith_short_8","alias_value":"K4Q42LAP","created_at":"2026-07-04T14:10:54.779224+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR","json":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR.json","graph_json":"https://pith.science/api/pith-number/K4Q42LAP2WSDGFS4OVHTXBM7RR/graph.json","events_json":"https://pith.science/api/pith-number/K4Q42LAP2WSDGFS4OVHTXBM7RR/events.json","paper":"https://pith.science/paper/K4Q42LAP"},"agent_actions":{"view_html":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR","download_json":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR.json","view_paper":"https://pith.science/paper/K4Q42LAP","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=astro-ph/0011548&json=true","fetch_graph":"https://pith.science/api/pith-number/K4Q42LAP2WSDGFS4OVHTXBM7RR/graph.json","fetch_events":"https://pith.science/api/pith-number/K4Q42LAP2WSDGFS4OVHTXBM7RR/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR/action/timestamp_anchor","attest_storage":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR/action/storage_attestation","attest_author":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR/action/author_attestation","sign_citation":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR/action/citation_signature","submit_replication":"https://pith.science/pith/K4Q42LAP2WSDGFS4OVHTXBM7RR/action/replication_record"}},"created_at":"2026-07-04T14:10:54.779224+00:00","updated_at":"2026-07-04T14:10:54.779224+00:00"}