{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:KHL5MPG7EWJUA5PFGNSTXPDVTX","short_pith_number":"pith:KHL5MPG7","canonical_record":{"source":{"id":"1202.4277","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-02-20T10:12:33Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"39ca5c3c1da6773e3df7344fc60766a53bd2a23eca400f89bea7c4ab7f73fde0","abstract_canon_sha256":"5c03b5a3001ac3a2ba8600a3d090aad4fa1f5123fc02dc08409fbc1e5742642e"},"schema_version":"1.0"},"canonical_sha256":"51d7d63cdf25934075e533653bbc759deed541f1d4e4b168858d4ffd1a13adc8","source":{"kind":"arxiv","id":"1202.4277","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1202.4277","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"arxiv_version","alias_value":"1202.4277v3","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1202.4277","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"pith_short_12","alias_value":"KHL5MPG7EWJU","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_16","alias_value":"KHL5MPG7EWJUA5PF","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_8","alias_value":"KHL5MPG7","created_at":"2026-05-18T12:27:11Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:KHL5MPG7EWJUA5PFGNSTXPDVTX","target":"record","payload":{"canonical_record":{"source":{"id":"1202.4277","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-02-20T10:12:33Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"39ca5c3c1da6773e3df7344fc60766a53bd2a23eca400f89bea7c4ab7f73fde0","abstract_canon_sha256":"5c03b5a3001ac3a2ba8600a3d090aad4fa1f5123fc02dc08409fbc1e5742642e"},"schema_version":"1.0"},"canonical_sha256":"51d7d63cdf25934075e533653bbc759deed541f1d4e4b168858d4ffd1a13adc8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:58:23.626970Z","signature_b64":"ZRIdXVEgzNev2P0T5cysb+aNMMowLULa9yaIS4OjUen9Gmtlczn4I2YE0LSgAongmMUeZSARxuZK0k+Ym4i3Bw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"51d7d63cdf25934075e533653bbc759deed541f1d4e4b168858d4ffd1a13adc8","last_reissued_at":"2026-05-18T01:58:23.626372Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:58:23.626372Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1202.4277","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:58:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CH+OpTM3NqHNkC1XN9D9uhrdptsxds265Cw00M3MneQ9UVjnPDHJd+gBLcnGK4gqQwEDcdXPRy6GwX4Nop8yDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T07:04:02.400051Z"},"content_sha256":"f6f9a9ea56ce16e07cb6a5f2c21afe830c83f47bba1b276f20a0bd6ab178df91","schema_version":"1.0","event_id":"sha256:f6f9a9ea56ce16e07cb6a5f2c21afe830c83f47bba1b276f20a0bd6ab178df91"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:KHL5MPG7EWJUA5PFGNSTXPDVTX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Density Independent Formulation of Smoothed Particle Hydrodynamics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.CO","authors_text":"Junichiro Makino, Takayuki R.Saitoh","submitted_at":"2012-02-20T10:12:33Z","abstract_excerpt":"The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low (high) density side is over (under) estimated. Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1202.4277","kind":"arxiv","version":3},"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":"2026-05-18T01:58:23Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YXW1dUcR6eP7+vMgKUixtntBaVlMIrKxhNDGunrlSa59VIvLovqdWEB1tqoTIDDudZwv4fsUgnIoxsk5WxgiBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T07:04:02.400457Z"},"content_sha256":"747be1eb95710dcc7d6907481d714f595ced5ec65effe75947dc2ac15477e2dd","schema_version":"1.0","event_id":"sha256:747be1eb95710dcc7d6907481d714f595ced5ec65effe75947dc2ac15477e2dd"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/bundle.json","state_url":"https://pith.science/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/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":"2026-06-01T07:04:02Z","links":{"resolver":"https://pith.science/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX","bundle":"https://pith.science/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/bundle.json","state":"https://pith.science/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/KHL5MPG7EWJUA5PFGNSTXPDVTX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:KHL5MPG7EWJUA5PFGNSTXPDVTX","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":"5c03b5a3001ac3a2ba8600a3d090aad4fa1f5123fc02dc08409fbc1e5742642e","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-02-20T10:12:33Z","title_canon_sha256":"39ca5c3c1da6773e3df7344fc60766a53bd2a23eca400f89bea7c4ab7f73fde0"},"schema_version":"1.0","source":{"id":"1202.4277","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1202.4277","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"arxiv_version","alias_value":"1202.4277v3","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1202.4277","created_at":"2026-05-18T01:58:23Z"},{"alias_kind":"pith_short_12","alias_value":"KHL5MPG7EWJU","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_16","alias_value":"KHL5MPG7EWJUA5PF","created_at":"2026-05-18T12:27:11Z"},{"alias_kind":"pith_short_8","alias_value":"KHL5MPG7","created_at":"2026-05-18T12:27:11Z"}],"graph_snapshots":[{"event_id":"sha256:747be1eb95710dcc7d6907481d714f595ced5ec65effe75947dc2ac15477e2dd","target":"graph","created_at":"2026-05-18T01:58:23Z","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":"The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low (high) density side is over (under) estimated. Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective s","authors_text":"Junichiro Makino, Takayuki R.Saitoh","cross_cats":["astro-ph.IM"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-02-20T10:12:33Z","title":"A Density Independent Formulation of Smoothed Particle Hydrodynamics"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1202.4277","kind":"arxiv","version":3},"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:f6f9a9ea56ce16e07cb6a5f2c21afe830c83f47bba1b276f20a0bd6ab178df91","target":"record","created_at":"2026-05-18T01:58:23Z","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":"5c03b5a3001ac3a2ba8600a3d090aad4fa1f5123fc02dc08409fbc1e5742642e","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-02-20T10:12:33Z","title_canon_sha256":"39ca5c3c1da6773e3df7344fc60766a53bd2a23eca400f89bea7c4ab7f73fde0"},"schema_version":"1.0","source":{"id":"1202.4277","kind":"arxiv","version":3}},"canonical_sha256":"51d7d63cdf25934075e533653bbc759deed541f1d4e4b168858d4ffd1a13adc8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"51d7d63cdf25934075e533653bbc759deed541f1d4e4b168858d4ffd1a13adc8","first_computed_at":"2026-05-18T01:58:23.626372Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:58:23.626372Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ZRIdXVEgzNev2P0T5cysb+aNMMowLULa9yaIS4OjUen9Gmtlczn4I2YE0LSgAongmMUeZSARxuZK0k+Ym4i3Bw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:58:23.626970Z","signed_message":"canonical_sha256_bytes"},"source_id":"1202.4277","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f6f9a9ea56ce16e07cb6a5f2c21afe830c83f47bba1b276f20a0bd6ab178df91","sha256:747be1eb95710dcc7d6907481d714f595ced5ec65effe75947dc2ac15477e2dd"],"state_sha256":"e03452844aa92fb72c5e78bcff0e5be83db577d5bade28e256df800b3ada59ef"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0vY79ezgdNb6HAJPxfFDQRTJaxcv8feW3O9rw1CGMdzmVTA3vC+flHC4zdPQBeHoZ2D0ZVh1nNSn+Y4I3evGBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T07:04:02.402512Z","bundle_sha256":"2ec1e60fba0021243b7db34d773cd16c8d55af077f26be0c76a7f6fb55c243ea"}}