{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:NXYKSM3KRTVSYJB5IB5QWPXCQ7","short_pith_number":"pith:NXYKSM3K","canonical_record":{"source":{"id":"2505.24343","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2025-05-30T08:34:55Z","cross_cats_sorted":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"title_canon_sha256":"d28bafa1caa15ee65ed89406012d03d8775f6387a7108c86c5948c8a311db89a","abstract_canon_sha256":"07871838dbd8dabeeba614f3c9a5efd49c53bccc91e8c8c7afff154454421229"},"schema_version":"1.0"},"canonical_sha256":"6df0a9336a8ceb2c243d407b0b3ee287ee099f0479ee5af2dd40b35f1f6c11e2","source":{"kind":"arxiv","id":"2505.24343","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.24343","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"arxiv_version","alias_value":"2505.24343v1","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.24343","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_12","alias_value":"NXYKSM3KRTVS","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_16","alias_value":"NXYKSM3KRTVSYJB5","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_8","alias_value":"NXYKSM3K","created_at":"2026-07-05T11:12:47Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:NXYKSM3KRTVSYJB5IB5QWPXCQ7","target":"record","payload":{"canonical_record":{"source":{"id":"2505.24343","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2025-05-30T08:34:55Z","cross_cats_sorted":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"title_canon_sha256":"d28bafa1caa15ee65ed89406012d03d8775f6387a7108c86c5948c8a311db89a","abstract_canon_sha256":"07871838dbd8dabeeba614f3c9a5efd49c53bccc91e8c8c7afff154454421229"},"schema_version":"1.0"},"canonical_sha256":"6df0a9336a8ceb2c243d407b0b3ee287ee099f0479ee5af2dd40b35f1f6c11e2","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:12:47.225214Z","signature_b64":"udfhBr84Dug4lOGGJ76plV78n5g7AB3a21RU/rUq50FcYuDor7Wu0gN87IUAGvMywXfefAJm0nHKuIk2WMhQCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6df0a9336a8ceb2c243d407b0b3ee287ee099f0479ee5af2dd40b35f1f6c11e2","last_reissued_at":"2026-07-05T11:12:47.224746Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:12:47.224746Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2505.24343","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":"2026-07-05T11:12:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ObLt4oGg743b0n0xifwJJLll1Fl6A6P2PixQI0Qj8iFRNCh2GgQDghxLQPNwREMz/8A+rdi0AlgHlLX6a6fzBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-09T11:44:35.160946Z"},"content_sha256":"199c6cc4ded0ff2f7ff25424a5ce023143c66c5dc0dcb9f5ea8eaa199f0a21f9","schema_version":"1.0","event_id":"sha256:199c6cc4ded0ff2f7ff25424a5ce023143c66c5dc0dcb9f5ea8eaa199f0a21f9"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:NXYKSM3KRTVSYJB5IB5QWPXCQ7","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Minimising the numerical viscosity in Smoothed Particle Hydrodynamics simulations of discs","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"primary_cat":"astro-ph.SR","authors_text":"Cheng Chen, C. J. Nixon","submitted_at":"2025-05-30T08:34:55Z","abstract_excerpt":"Simulations using the Smoothed Particle Hydrodynamics (SPH) technique typically include numerical viscosity to model shocks and maintain particle order on the kernel scale. This numerical viscosity is composed of linear and quadratic terms, with coefficients $\\alpha_{\\rm SPH}$ and $\\beta_{\\rm SPH}$ respectively. Setting these coefficients too high results in excessive numerical dissipation, whereas setting them too low may lead to unwanted effects such as particle penetration, which also leads to excess dissipation. In this study, we simulate accretion discs using the SPH code {\\sc phantom} to"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.24343","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2505.24343/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T11:12:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"PhE75EQIG5I/bh4MkflOfzcaO7iqwVJWV9I8tiSNsNX7YdF9dAFh37WR9Wm0w/W0ZYVl7LepXKeTY4s24KlcCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-09T11:44:35.161473Z"},"content_sha256":"7e229c7f3c49cd9b9484dd5dc4f4793614b9b89a726ff626719b0ec4e6fc72cc","schema_version":"1.0","event_id":"sha256:7e229c7f3c49cd9b9484dd5dc4f4793614b9b89a726ff626719b0ec4e6fc72cc"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/bundle.json","state_url":"https://pith.science/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/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":"2026-08-09T11:44:35Z","links":{"resolver":"https://pith.science/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7","bundle":"https://pith.science/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/bundle.json","state":"https://pith.science/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/state.json","well_known_bundle":"https://pith.science/.well-known/pith/NXYKSM3KRTVSYJB5IB5QWPXCQ7/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:NXYKSM3KRTVSYJB5IB5QWPXCQ7","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":"07871838dbd8dabeeba614f3c9a5efd49c53bccc91e8c8c7afff154454421229","cross_cats_sorted":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2025-05-30T08:34:55Z","title_canon_sha256":"d28bafa1caa15ee65ed89406012d03d8775f6387a7108c86c5948c8a311db89a"},"schema_version":"1.0","source":{"id":"2505.24343","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.24343","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"arxiv_version","alias_value":"2505.24343v1","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.24343","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_12","alias_value":"NXYKSM3KRTVS","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_16","alias_value":"NXYKSM3KRTVSYJB5","created_at":"2026-07-05T11:12:47Z"},{"alias_kind":"pith_short_8","alias_value":"NXYKSM3K","created_at":"2026-07-05T11:12:47Z"}],"graph_snapshots":[{"event_id":"sha256:7e229c7f3c49cd9b9484dd5dc4f4793614b9b89a726ff626719b0ec4e6fc72cc","target":"graph","created_at":"2026-07-05T11:12:47Z","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/2505.24343/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Simulations using the Smoothed Particle Hydrodynamics (SPH) technique typically include numerical viscosity to model shocks and maintain particle order on the kernel scale. This numerical viscosity is composed of linear and quadratic terms, with coefficients $\\alpha_{\\rm SPH}$ and $\\beta_{\\rm SPH}$ respectively. Setting these coefficients too high results in excessive numerical dissipation, whereas setting them too low may lead to unwanted effects such as particle penetration, which also leads to excess dissipation. In this study, we simulate accretion discs using the SPH code {\\sc phantom} to","authors_text":"Cheng Chen, C. J. Nixon","cross_cats":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2025-05-30T08:34:55Z","title":"Minimising the numerical viscosity in Smoothed Particle Hydrodynamics simulations of discs"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.24343","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":"sha256:199c6cc4ded0ff2f7ff25424a5ce023143c66c5dc0dcb9f5ea8eaa199f0a21f9","target":"record","created_at":"2026-07-05T11:12:47Z","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":"07871838dbd8dabeeba614f3c9a5efd49c53bccc91e8c8c7afff154454421229","cross_cats_sorted":["astro-ph.EP","astro-ph.HE","astro-ph.IM"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.SR","submitted_at":"2025-05-30T08:34:55Z","title_canon_sha256":"d28bafa1caa15ee65ed89406012d03d8775f6387a7108c86c5948c8a311db89a"},"schema_version":"1.0","source":{"id":"2505.24343","kind":"arxiv","version":1}},"canonical_sha256":"6df0a9336a8ceb2c243d407b0b3ee287ee099f0479ee5af2dd40b35f1f6c11e2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6df0a9336a8ceb2c243d407b0b3ee287ee099f0479ee5af2dd40b35f1f6c11e2","first_computed_at":"2026-07-05T11:12:47.224746Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:12:47.224746Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"udfhBr84Dug4lOGGJ76plV78n5g7AB3a21RU/rUq50FcYuDor7Wu0gN87IUAGvMywXfefAJm0nHKuIk2WMhQCw==","signature_status":"signed_v1","signed_at":"2026-07-05T11:12:47.225214Z","signed_message":"canonical_sha256_bytes"},"source_id":"2505.24343","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:199c6cc4ded0ff2f7ff25424a5ce023143c66c5dc0dcb9f5ea8eaa199f0a21f9","sha256:7e229c7f3c49cd9b9484dd5dc4f4793614b9b89a726ff626719b0ec4e6fc72cc"],"state_sha256":"d2762175e552d96457d44c2ca20c9f3c43c1b30232f88dc3c8f2730883b4812f"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UkH1h1qYFO3fdqhUnNFcmmy/kh+XBOlA2I8XSSy/ZZcovOFwqhaPiQDmor/bAA/G0mV4F7kQ5wJSwYIk3CxKAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-09T11:44:35.166969Z","bundle_sha256":"8ad15cd14102f29c1430113ae69e3532ea26ef3c8b4d20cd7be15552afd68a9b"}}