{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2007:ASDNIPJCA2TTH37Q7DJLTH3VAF","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":"c432156700946bef364899bdbc8d83069b2455a2086bfc11a8c869bb4555e183","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2007-01-31T15:31:51Z","title_canon_sha256":"12160bc5917137637ee3267b886c6d0a13cb64d503c88620934d3cea6ba51e7a"},"schema_version":"1.0","source":{"id":"astro-ph/0701909","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0701909","created_at":"2026-05-18T01:40:27Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0701909v1","created_at":"2026-05-18T01:40:27Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0701909","created_at":"2026-05-18T01:40:27Z"},{"alias_kind":"pith_short_12","alias_value":"ASDNIPJCA2TT","created_at":"2026-05-18T12:25:55Z"},{"alias_kind":"pith_short_16","alias_value":"ASDNIPJCA2TTH37Q","created_at":"2026-05-18T12:25:55Z"},{"alias_kind":"pith_short_8","alias_value":"ASDNIPJC","created_at":"2026-05-18T12:25:55Z"}],"graph_snapshots":[{"event_id":"sha256:0da76e1c4578924a421a64fc59ddeaf4c31aa0d9b50882f22a78631ca62d09a3","target":"graph","created_at":"2026-05-18T01:40:27Z","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":"Context: There is a need to improve the fidelity of SPH simulations of self-gravitating gas dynamics. Aims: We remind users of SPH that, if smoothing lengths are adjusted so as to keep the number of neighbours, ${\\cal N}$, in the range ${\\cal N}_{_{\\rm NEIB}}\\pm\\Delta{\\cal N}_{_{\\rm NEIB}}$, the tolerance, $\\Delta{\\cal N}_{_{\\rm NEIB}}$, should be set to zero, as first noted by Nelson & Papaloizou. We point out that this is a very straightforward and computationally inexpensive constraint to implement. Methods: We demonstrate this by simulating acoustic oscillations of a self-gravitating isent","authors_text":"A. P. Whitworth, R. E. Attwood, S. P. Goodwin","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2007-01-31T15:31:51Z","title":"Adaptive smoothing lengths in SPH"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0701909","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:a491910fa10eecd7083d0acda16973814105bef2a4c0549d249fe99c13462bc7","target":"record","created_at":"2026-05-18T01:40:27Z","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":"c432156700946bef364899bdbc8d83069b2455a2086bfc11a8c869bb4555e183","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2007-01-31T15:31:51Z","title_canon_sha256":"12160bc5917137637ee3267b886c6d0a13cb64d503c88620934d3cea6ba51e7a"},"schema_version":"1.0","source":{"id":"astro-ph/0701909","kind":"arxiv","version":1}},"canonical_sha256":"0486d43d2206a733eff0f8d2b99f75016e4c11ff78c248c3117bdadabc806cdc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0486d43d2206a733eff0f8d2b99f75016e4c11ff78c248c3117bdadabc806cdc","first_computed_at":"2026-05-18T01:40:27.011524Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:40:27.011524Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"KNs2hVRXxlHFZ/hgvZSgKPuSzG7E29Lv46w09pA+sfo9ggip115lhj8NNlnPOZX2AK+rYFH9rb0gllblZFWTAA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:40:27.012106Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0701909","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a491910fa10eecd7083d0acda16973814105bef2a4c0549d249fe99c13462bc7","sha256:0da76e1c4578924a421a64fc59ddeaf4c31aa0d9b50882f22a78631ca62d09a3"],"state_sha256":"0e6f2580f6b8c1eaf37fe335d5bcf2274144aa58fc5b95ea943819c2ea1025b1"}