{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1997:CSI5PWJWEASPBTUFQX7YATVDJU","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":"24a7ca1ecc5da85d3f09a0ce335edf6a8b3ad55d37155694c3b9626c05fde173","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"1997-06-20T20:37:34Z","title_canon_sha256":"27afeed34cd55d85ad73cdfec0fa4885dd0e741f4f0db04cbe5919b99836ba5c"},"schema_version":"1.0","source":{"id":"astro-ph/9706219","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/9706219","created_at":"2026-07-04T16:03:04Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/9706219v1","created_at":"2026-07-04T16:03:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/9706219","created_at":"2026-07-04T16:03:04Z"},{"alias_kind":"pith_short_12","alias_value":"CSI5PWJWEASP","created_at":"2026-07-04T16:03:04Z"},{"alias_kind":"pith_short_16","alias_value":"CSI5PWJWEASPBTUF","created_at":"2026-07-04T16:03:04Z"},{"alias_kind":"pith_short_8","alias_value":"CSI5PWJW","created_at":"2026-07-04T16:03:04Z"}],"graph_snapshots":[{"event_id":"sha256:80844af61612d086c2e11f64050e752660c46f93071aac5e04878b437b088a1a","target":"graph","created_at":"2026-07-04T16:03:04Z","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/astro-ph/9706219/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We introduce an efficient and accurate alternative to full hydrodynamic simulations, Hydro-PM (HPM), for the study of the low column density Lyman-alpha forest. It consists of a Particle-Mesh solver, modified to compute, in addition to the gravitational potential, an effective potential due to the gas pressure. Such an effective potential can be computed from the density field because of a tight correlation between density and pressure in the low density limit, which can be calculated for any photo-reionization history by a method outlined in Hui & Gnedin (1997). Such a correlation exists, in ","authors_text":"Lam Hui, Nickolay Y. Gnedin","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"1997-06-20T20:37:34Z","title":"Probing the Universe with the Lyman-alpha Forest: I. Hydrodynamics of the Low Density IGM"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9706219","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:f6c347101fa2bd6c98ba6638fe11c3b41039434dcfdac7da982192be9f5e6b04","target":"record","created_at":"2026-07-04T16:03:04Z","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":"24a7ca1ecc5da85d3f09a0ce335edf6a8b3ad55d37155694c3b9626c05fde173","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"1997-06-20T20:37:34Z","title_canon_sha256":"27afeed34cd55d85ad73cdfec0fa4885dd0e741f4f0db04cbe5919b99836ba5c"},"schema_version":"1.0","source":{"id":"astro-ph/9706219","kind":"arxiv","version":1}},"canonical_sha256":"1491d7d9362024f0ce8585ff804ea34d2e3e09a01b98b9785da64168a3b642fb","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1491d7d9362024f0ce8585ff804ea34d2e3e09a01b98b9785da64168a3b642fb","first_computed_at":"2026-07-04T16:03:04.560172Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T16:03:04.560172Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Sev8M36zZpuRcAbFrGkdKSfxDvVeX0o3CGdQrmmHOsTGvRxkUbGG3ofppEc16NKvAqOSdW4nzPiuNNNIBAnXCQ==","signature_status":"signed_v1","signed_at":"2026-07-04T16:03:04.560534Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/9706219","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f6c347101fa2bd6c98ba6638fe11c3b41039434dcfdac7da982192be9f5e6b04","sha256:80844af61612d086c2e11f64050e752660c46f93071aac5e04878b437b088a1a"],"state_sha256":"12e284f9be4ade965b091eecdb369251dfe65a2ed4ff6386624034bdd19d0e5d"}