{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:1998:U7I2M4CAJDMWNODYNILISWKVVS","short_pith_number":"pith:U7I2M4CA","canonical_record":{"source":{"id":"astro-ph/9807121","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"1998-07-13T15:25:26Z","cross_cats_sorted":[],"title_canon_sha256":"10184fbf1b1d46fbaab5fca9af80bdfa35ea4ced74ce5e94a2e3df2205d3c730","abstract_canon_sha256":"9cf8b00dcc83009c64302050dde27ec8bd7174426b204398f3b6f135f018aaf9"},"schema_version":"1.0"},"canonical_sha256":"a7d1a6704048d966b8786a16895955ac9017c2cb1d0c4b4477dfa11d939ef8d9","source":{"kind":"arxiv","id":"astro-ph/9807121","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/9807121","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/9807121v1","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/9807121","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"pith_short_12","alias_value":"U7I2M4CAJDMW","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"U7I2M4CAJDMWNODY","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"U7I2M4CA","created_at":"2026-05-18T12:25:49Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:1998:U7I2M4CAJDMWNODYNILISWKVVS","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/9807121","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"1998-07-13T15:25:26Z","cross_cats_sorted":[],"title_canon_sha256":"10184fbf1b1d46fbaab5fca9af80bdfa35ea4ced74ce5e94a2e3df2205d3c730","abstract_canon_sha256":"9cf8b00dcc83009c64302050dde27ec8bd7174426b204398f3b6f135f018aaf9"},"schema_version":"1.0"},"canonical_sha256":"a7d1a6704048d966b8786a16895955ac9017c2cb1d0c4b4477dfa11d939ef8d9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:21:56.463675Z","signature_b64":"M349KaX/B4/jgIRaMnDkM1+R/5vVlSgsJnjVNC+ZDMPXvFxI3BNJB8i8J7a6cF3fhbE9NdDEPFZOPFTceevEBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a7d1a6704048d966b8786a16895955ac9017c2cb1d0c4b4477dfa11d939ef8d9","last_reissued_at":"2026-05-18T01:21:56.462996Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:21:56.462996Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/9807121","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:21:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"q64zJYYEMb0Q9n7wO/Mvn6Ns3EzjYv93qU55k73e/LvOyogjzQW9doB4zrUw/TXaS3Pfk7OUU7w8GAaRQ6E3AA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:32:20.429249Z"},"content_sha256":"9b447d6fcf562a5123bc8c1c8c74ac35c69125de817ae70bd9c976644a37c578","schema_version":"1.0","event_id":"sha256:9b447d6fcf562a5123bc8c1c8c74ac35c69125de817ae70bd9c976644a37c578"},{"event_type":"graph_snapshot","subject_pith_number":"pith:1998:U7I2M4CAJDMWNODYNILISWKVVS","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Cosmological Adaptive Mesh Refinement","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Greg L. Bryan, Michael L. Norman","submitted_at":"1998-07-13T15:25:26Z","abstract_excerpt":"We describe a grid-based numerical method for 3D hydrodynamic cosmological simulations which is adaptive in space and time and combines the best features of higher order--accurate Godunov schemes for Eulerian hydrodynamics with adaptive particle--mesh methods for collisionless particles. The basis for our method is the structured adaptive mesh refinement (AMR) algorithm of Berger & Collela (1989), which we have extended to cosmological hydro + N-body simulations. The resulting multiscale hybrid method is a powerful alternative to particle-based methods in current use. The choices we have made "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9807121","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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":"2026-05-18T01:21:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GPnD3+9/Yq3I3Xa4WXF5hbKvgV8JRNOucxGo+GwtD9+8vFhpodwQ99z+dMCLm8Hsm28msf9NiSMq7KjyPDJoBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:32:20.429607Z"},"content_sha256":"37e8958af2e73f1a972155fae74005d78b05442ea685f104373fdc1defdcb873","schema_version":"1.0","event_id":"sha256:37e8958af2e73f1a972155fae74005d78b05442ea685f104373fdc1defdcb873"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/U7I2M4CAJDMWNODYNILISWKVVS/bundle.json","state_url":"https://pith.science/pith/U7I2M4CAJDMWNODYNILISWKVVS/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/U7I2M4CAJDMWNODYNILISWKVVS/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":"2026-05-30T06:32:20Z","links":{"resolver":"https://pith.science/pith/U7I2M4CAJDMWNODYNILISWKVVS","bundle":"https://pith.science/pith/U7I2M4CAJDMWNODYNILISWKVVS/bundle.json","state":"https://pith.science/pith/U7I2M4CAJDMWNODYNILISWKVVS/state.json","well_known_bundle":"https://pith.science/.well-known/pith/U7I2M4CAJDMWNODYNILISWKVVS/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1998:U7I2M4CAJDMWNODYNILISWKVVS","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":"9cf8b00dcc83009c64302050dde27ec8bd7174426b204398f3b6f135f018aaf9","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"1998-07-13T15:25:26Z","title_canon_sha256":"10184fbf1b1d46fbaab5fca9af80bdfa35ea4ced74ce5e94a2e3df2205d3c730"},"schema_version":"1.0","source":{"id":"astro-ph/9807121","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/9807121","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/9807121v1","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/9807121","created_at":"2026-05-18T01:21:56Z"},{"alias_kind":"pith_short_12","alias_value":"U7I2M4CAJDMW","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"U7I2M4CAJDMWNODY","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"U7I2M4CA","created_at":"2026-05-18T12:25:49Z"}],"graph_snapshots":[{"event_id":"sha256:37e8958af2e73f1a972155fae74005d78b05442ea685f104373fdc1defdcb873","target":"graph","created_at":"2026-05-18T01:21:56Z","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":"We describe a grid-based numerical method for 3D hydrodynamic cosmological simulations which is adaptive in space and time and combines the best features of higher order--accurate Godunov schemes for Eulerian hydrodynamics with adaptive particle--mesh methods for collisionless particles. The basis for our method is the structured adaptive mesh refinement (AMR) algorithm of Berger & Collela (1989), which we have extended to cosmological hydro + N-body simulations. The resulting multiscale hybrid method is a powerful alternative to particle-based methods in current use. The choices we have made ","authors_text":"Greg L. Bryan, Michael L. Norman","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"1998-07-13T15:25:26Z","title":"Cosmological Adaptive Mesh Refinement"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9807121","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":"sha256:9b447d6fcf562a5123bc8c1c8c74ac35c69125de817ae70bd9c976644a37c578","target":"record","created_at":"2026-05-18T01:21:56Z","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":"9cf8b00dcc83009c64302050dde27ec8bd7174426b204398f3b6f135f018aaf9","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"1998-07-13T15:25:26Z","title_canon_sha256":"10184fbf1b1d46fbaab5fca9af80bdfa35ea4ced74ce5e94a2e3df2205d3c730"},"schema_version":"1.0","source":{"id":"astro-ph/9807121","kind":"arxiv","version":1}},"canonical_sha256":"a7d1a6704048d966b8786a16895955ac9017c2cb1d0c4b4477dfa11d939ef8d9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a7d1a6704048d966b8786a16895955ac9017c2cb1d0c4b4477dfa11d939ef8d9","first_computed_at":"2026-05-18T01:21:56.462996Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:21:56.462996Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"M349KaX/B4/jgIRaMnDkM1+R/5vVlSgsJnjVNC+ZDMPXvFxI3BNJB8i8J7a6cF3fhbE9NdDEPFZOPFTceevEBg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:21:56.463675Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/9807121","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9b447d6fcf562a5123bc8c1c8c74ac35c69125de817ae70bd9c976644a37c578","sha256:37e8958af2e73f1a972155fae74005d78b05442ea685f104373fdc1defdcb873"],"state_sha256":"23709953b701361998c8d2c065faca3e1518ffeafac5aa8cbb6ecf237d055cd7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5CVEAOSeyKsTcHjILno62ulphVIijRUNehXqU1Cr45lE9LBj69XTO6g/GxhGF8jCOLorLuURuo1+eOmYpWhZDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T06:32:20.431582Z","bundle_sha256":"bd769904c248c5a7d9f907ebbf36ef5f0b17ecb0ac3c80228854a1c0c64f2c0f"}}