{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:42DZUVY2JTHJZAOM6LRU7DI2J7","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":"7ed31726f3977657e50d3a726f5ecc36f7edf8190c48610943ad79aa5bf416ed","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2009-04-13T07:21:30Z","title_canon_sha256":"3df06887ba63ad46dc386411514de14debc1d2cce124b4511f8b0973bf2d184a"},"schema_version":"1.0","source":{"id":"0904.1921","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.1921","created_at":"2026-05-18T04:08:24Z"},{"alias_kind":"arxiv_version","alias_value":"0904.1921v1","created_at":"2026-05-18T04:08:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.1921","created_at":"2026-05-18T04:08:24Z"},{"alias_kind":"pith_short_12","alias_value":"42DZUVY2JTHJ","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"42DZUVY2JTHJZAOM","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"42DZUVY2","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:705183cd7f7c55af807d97a2275a46cc721077940e1ff282b5ef11d9827edb30","target":"graph","created_at":"2026-05-18T04:08:24Z","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":"Angular momentum transport within young massive protoplanetary discs may be dominated by self-gravity at radii where the disk is too weakly ionized to allow the development of the magneto-rotational instability. We use time-dependent one-dimensional disc models, based on a local cooling time calculation of the efficiency of transport, to study the radial structure and stability (against fragmentation) of protoplanetary discs in which self-gravity is the sole transport mechanism. We find that self-gravitating discs rapidly attain a quasi-steady state in which the surface density in the inner di","authors_text":"P.J. Armitage, W.K.M. Rice","cross_cats":["astro-ph.EP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2009-04-13T07:21:30Z","title":"Time-dependent models of the structure and evolution of self-gravitating protoplanetary discs"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.1921","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:a634d34ad973233701ed0d4bbd0fd84f0b9c4ba8cf3e205c9e064662377bf58c","target":"record","created_at":"2026-05-18T04:08:24Z","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":"7ed31726f3977657e50d3a726f5ecc36f7edf8190c48610943ad79aa5bf416ed","cross_cats_sorted":["astro-ph.EP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2009-04-13T07:21:30Z","title_canon_sha256":"3df06887ba63ad46dc386411514de14debc1d2cce124b4511f8b0973bf2d184a"},"schema_version":"1.0","source":{"id":"0904.1921","kind":"arxiv","version":1}},"canonical_sha256":"e6879a571a4cce9c81ccf2e34f8d1a4ffd1c76f338faf88815a2dd383e1b45dc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e6879a571a4cce9c81ccf2e34f8d1a4ffd1c76f338faf88815a2dd383e1b45dc","first_computed_at":"2026-05-18T04:08:24.761230Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:08:24.761230Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"UkXZ47cN5uUlMveysTdBWnTDTQV+h3ML51+RdxQ2tm7W3kCEQltKCjYXyAHlvzhDaXpNzx9YA40kcyXo33arDA==","signature_status":"signed_v1","signed_at":"2026-05-18T04:08:24.761751Z","signed_message":"canonical_sha256_bytes"},"source_id":"0904.1921","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a634d34ad973233701ed0d4bbd0fd84f0b9c4ba8cf3e205c9e064662377bf58c","sha256:705183cd7f7c55af807d97a2275a46cc721077940e1ff282b5ef11d9827edb30"],"state_sha256":"24bc7837f5f7ccce28fd6af2275a70fadb7ea12a67b0c20b2c7a8dfc4c510428"}