{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:JBVIQTT5IAUOO36W4LQL7XXPSJ","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":"f37e9a5708949f37b8e7df5d72581bb717fbb703de52fdb1d29acad9f85289b7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2026-08-04T09:54:36Z","title_canon_sha256":"6b5010f4938adabfe8e1cbe80095164a2928d8f477915493b158b8020f77524c"},"schema_version":"1.0","source":{"id":"2608.03400","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2608.03400","created_at":"2026-08-05T01:35:46Z"},{"alias_kind":"arxiv_version","alias_value":"2608.03400v1","created_at":"2026-08-05T01:35:46Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2608.03400","created_at":"2026-08-05T01:35:46Z"},{"alias_kind":"pith_short_12","alias_value":"JBVIQTT5IAUO","created_at":"2026-08-05T01:35:46Z"},{"alias_kind":"pith_short_16","alias_value":"JBVIQTT5IAUOO36W","created_at":"2026-08-05T01:35:46Z"},{"alias_kind":"pith_short_8","alias_value":"JBVIQTT5","created_at":"2026-08-05T01:35:46Z"}],"graph_snapshots":[{"event_id":"sha256:6a37920585ad272dde3a49f64b63f421a4bb61faed66e39a44e13677454922ad","target":"graph","created_at":"2026-08-05T01:35:46Z","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/2608.03400/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"These lecture notes provide an introduction to the generation of initial conditions for cosmological N-body simulations. Starting from the definition and properties of Gaussian random fields, we discuss their role in cosmology and the efficient generation of such fields using Fourier methods. The Vlasov-Poisson system is introduced as the governing framework for cold collisionless matter, and its solution via characteristics and Lagrangian perturbation theory (LPT) is detailed. We discuss the use of LPT for initializing N-body simulations, emphasizing the importance of high-order LPT and late-","authors_text":"Oliver Hahn","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2026-08-04T09:54:36Z","title":"Bridging perturbation theory and simulations: initial conditions and fast integrators for cosmological simulations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2608.03400","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":"sha256:2b0e7b09811c27a14b7c7fd7a948cd59a0d73cf17d634879f4b1b94d3cc0676a","target":"record","created_at":"2026-08-05T01:35:46Z","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":"f37e9a5708949f37b8e7df5d72581bb717fbb703de52fdb1d29acad9f85289b7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2026-08-04T09:54:36Z","title_canon_sha256":"6b5010f4938adabfe8e1cbe80095164a2928d8f477915493b158b8020f77524c"},"schema_version":"1.0","source":{"id":"2608.03400","kind":"arxiv","version":1}},"canonical_sha256":"486a884e7d4028e76fd6e2e0bfdeef92447f879d1c9cbedc5212224661d03dec","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"486a884e7d4028e76fd6e2e0bfdeef92447f879d1c9cbedc5212224661d03dec","first_computed_at":"2026-08-05T01:35:46.157375Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-08-05T01:35:46.157375Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ajoU1Y0RlrH9CJepBcpEswAO9YAw/w+DbJ+LAVOlu4YNnqumX1lijn4VpPU7truSE8tu6Z4fWnuO+H41wSfYCQ==","signature_status":"signed_v1","signed_at":"2026-08-05T01:35:46.158868Z","signed_message":"canonical_sha256_bytes"},"source_id":"2608.03400","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:2b0e7b09811c27a14b7c7fd7a948cd59a0d73cf17d634879f4b1b94d3cc0676a","sha256:6a37920585ad272dde3a49f64b63f421a4bb61faed66e39a44e13677454922ad"],"state_sha256":"680b29192fbb5823f9b0151898d5ee78ff6d02094b6ec340a075a22fd6d69828"}