{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:MGLYW4EQOWVKZSMLNS6SC5TD2Q","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":"ab5b431fea06a0b4d285a18b21000a8439cb128ffba835d3bd3ec5e8f3fcabc2","cross_cats_sorted":["hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2018-02-09T14:13:36Z","title_canon_sha256":"ff8cb368d3ea8f3e91055f85365dca0abe9e1a5802545b588f6adbac8a2274e0"},"schema_version":"1.0","source":{"id":"1802.03267","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1802.03267","created_at":"2026-05-17T23:51:59Z"},{"alias_kind":"arxiv_version","alias_value":"1802.03267v2","created_at":"2026-05-17T23:51:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1802.03267","created_at":"2026-05-17T23:51:59Z"},{"alias_kind":"pith_short_12","alias_value":"MGLYW4EQOWVK","created_at":"2026-05-18T12:32:37Z"},{"alias_kind":"pith_short_16","alias_value":"MGLYW4EQOWVKZSML","created_at":"2026-05-18T12:32:37Z"},{"alias_kind":"pith_short_8","alias_value":"MGLYW4EQ","created_at":"2026-05-18T12:32:37Z"}],"graph_snapshots":[{"event_id":"sha256:fe24a9b485437c1f5a7eecfb6d440a9b96eae9a2d2c705445c18ce5bd4ed9f7b","target":"graph","created_at":"2026-05-17T23:51:59Z","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 analog acoustic metric has been originally derived for adiabatic acoustic perturbations propagating in an isentropic irrotational ideal fluid. In the framework of a Lagrangian hydrodynamic description we demonstrate that under certain conditions the usual acoustic metric can be derived for nonisentropic fluids. In a special case when the pressure takes a special form and the nonadiabatic perturbations are neglected the adiabatic acoustic perturbations corresponding to massless phonons propagate in an analog metric of the usual type.","authors_text":"Hrvoje Nikoli\\'c, Neven Bili\\'c","cross_cats":["hep-th"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2018-02-09T14:13:36Z","title":"Analog gravity in nonisentropic fluids"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1802.03267","kind":"arxiv","version":2},"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":"sha256:334897634e96d4a60e83cb15258852df37b1b7d29d39002c6c42c167be8dfa1f","target":"record","created_at":"2026-05-17T23:51:59Z","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":"ab5b431fea06a0b4d285a18b21000a8439cb128ffba835d3bd3ec5e8f3fcabc2","cross_cats_sorted":["hep-th"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2018-02-09T14:13:36Z","title_canon_sha256":"ff8cb368d3ea8f3e91055f85365dca0abe9e1a5802545b588f6adbac8a2274e0"},"schema_version":"1.0","source":{"id":"1802.03267","kind":"arxiv","version":2}},"canonical_sha256":"61978b709075aaacc98b6cbd217663d43a993b5e32528767c00e8b68d1916354","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"61978b709075aaacc98b6cbd217663d43a993b5e32528767c00e8b68d1916354","first_computed_at":"2026-05-17T23:51:59.087918Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:51:59.087918Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"B6r89bxyOYu1nS1o7JcpGNLihfr6XDLmCFmJVrKfBjuu4e27JAeHzJBOO46Dj8c8Pj2DeNODJ3dSq8z0J/UiAw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:51:59.088273Z","signed_message":"canonical_sha256_bytes"},"source_id":"1802.03267","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:334897634e96d4a60e83cb15258852df37b1b7d29d39002c6c42c167be8dfa1f","sha256:fe24a9b485437c1f5a7eecfb6d440a9b96eae9a2d2c705445c18ce5bd4ed9f7b"],"state_sha256":"bda8097eb6e099a0afec9d2182b20dedbeeb13f12a64e0b497b681c73e5b6d8a"}