{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:QY4RP6CJH6I3IEH554VX5NRKQN","short_pith_number":"pith:QY4RP6CJ","canonical_record":{"source":{"id":"1907.08542","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-19T15:12:30Z","cross_cats_sorted":["astro-ph.GA","astro-ph.SR"],"title_canon_sha256":"c56795f8e5c3648f5d2585cefbc3c00096234cb9bd5d7b9c95cb625042bbeaab","abstract_canon_sha256":"9442012a386024e86474d1ab1ee7664f54bb6ef058d24e6ed0c79d23d93c0a06"},"schema_version":"1.0"},"canonical_sha256":"863917f8493f91b410fdef2b7eb62a834fdcb5aa58d06e737650312c637a3cfe","source":{"kind":"arxiv","id":"1907.08542","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.08542","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"arxiv_version","alias_value":"1907.08542v1","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.08542","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"pith_short_12","alias_value":"QY4RP6CJH6I3","created_at":"2026-05-18T12:33:27Z"},{"alias_kind":"pith_short_16","alias_value":"QY4RP6CJH6I3IEH5","created_at":"2026-05-18T12:33:27Z"},{"alias_kind":"pith_short_8","alias_value":"QY4RP6CJ","created_at":"2026-05-18T12:33:27Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:QY4RP6CJH6I3IEH554VX5NRKQN","target":"record","payload":{"canonical_record":{"source":{"id":"1907.08542","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-19T15:12:30Z","cross_cats_sorted":["astro-ph.GA","astro-ph.SR"],"title_canon_sha256":"c56795f8e5c3648f5d2585cefbc3c00096234cb9bd5d7b9c95cb625042bbeaab","abstract_canon_sha256":"9442012a386024e86474d1ab1ee7664f54bb6ef058d24e6ed0c79d23d93c0a06"},"schema_version":"1.0"},"canonical_sha256":"863917f8493f91b410fdef2b7eb62a834fdcb5aa58d06e737650312c637a3cfe","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:40:09.475086Z","signature_b64":"gMl4pGVHcWSRBOi9TOhO7b+//cyCWuWXhsPwzzfbXKY1nqZZz8C5choFpa2c5FQuWvCChYXAe6kxbnrrfDf7DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"863917f8493f91b410fdef2b7eb62a834fdcb5aa58d06e737650312c637a3cfe","last_reissued_at":"2026-05-17T23:40:09.471404Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:40:09.471404Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1907.08542","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":"2026-05-17T23:40:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lCX+O61k78LAvxioE+x3RK/DqxsZ81DpUM+FnWahWD+QT+Oc+cS75hxa6HjzOzRdA8ntRwtd0igPDCuMS2jcDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T09:36:04.940519Z"},"content_sha256":"88586dd9e96ab372c36dd7d67d47ac5b1257429492db556fa368f31eb56daa39","schema_version":"1.0","event_id":"sha256:88586dd9e96ab372c36dd7d67d47ac5b1257429492db556fa368f31eb56daa39"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:QY4RP6CJH6I3IEH554VX5NRKQN","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Numerical Methods for Simulating Star Formation","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.GA","astro-ph.SR"],"primary_cat":"astro-ph.IM","authors_text":"Benoit Commercon, Romain Teyssier","submitted_at":"2019-07-19T15:12:30Z","abstract_excerpt":"We review the numerical techniques for ideal and non-ideal magneto-hydrodynamics (MHD) used in the context of star formation simulations. We outline the specific challenges offered by modeling star forming environments, which are dominated by supersonic and super-Alfvenic turbulence in a radiative, self-gravitating fluid. These conditions are rather unique in physics and engineering and pose particularly severe restrictions on the robustness and accuracy of numerical codes. One striking aspect is the formation of collapsing fluid elements leading to the formation of singularities that represen"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.08542","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":"2026-05-17T23:40:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"p9hgUrjX0Y9vXgApq4xQxP+bvB0tS4SpATcqJcRLAro9NRXUGWfBvB/XYpRhJKDeuAff9AYTHSpRsEhk81eBCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T09:36:04.941077Z"},"content_sha256":"3499b4389ba657e1d9f6799589060cdfb5097435661e27a92e58b08ffab4aca1","schema_version":"1.0","event_id":"sha256:3499b4389ba657e1d9f6799589060cdfb5097435661e27a92e58b08ffab4aca1"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QY4RP6CJH6I3IEH554VX5NRKQN/bundle.json","state_url":"https://pith.science/pith/QY4RP6CJH6I3IEH554VX5NRKQN/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QY4RP6CJH6I3IEH554VX5NRKQN/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":"2026-06-07T09:36:04Z","links":{"resolver":"https://pith.science/pith/QY4RP6CJH6I3IEH554VX5NRKQN","bundle":"https://pith.science/pith/QY4RP6CJH6I3IEH554VX5NRKQN/bundle.json","state":"https://pith.science/pith/QY4RP6CJH6I3IEH554VX5NRKQN/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QY4RP6CJH6I3IEH554VX5NRKQN/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:QY4RP6CJH6I3IEH554VX5NRKQN","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":"9442012a386024e86474d1ab1ee7664f54bb6ef058d24e6ed0c79d23d93c0a06","cross_cats_sorted":["astro-ph.GA","astro-ph.SR"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-19T15:12:30Z","title_canon_sha256":"c56795f8e5c3648f5d2585cefbc3c00096234cb9bd5d7b9c95cb625042bbeaab"},"schema_version":"1.0","source":{"id":"1907.08542","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.08542","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"arxiv_version","alias_value":"1907.08542v1","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.08542","created_at":"2026-05-17T23:40:09Z"},{"alias_kind":"pith_short_12","alias_value":"QY4RP6CJH6I3","created_at":"2026-05-18T12:33:27Z"},{"alias_kind":"pith_short_16","alias_value":"QY4RP6CJH6I3IEH5","created_at":"2026-05-18T12:33:27Z"},{"alias_kind":"pith_short_8","alias_value":"QY4RP6CJ","created_at":"2026-05-18T12:33:27Z"}],"graph_snapshots":[{"event_id":"sha256:3499b4389ba657e1d9f6799589060cdfb5097435661e27a92e58b08ffab4aca1","target":"graph","created_at":"2026-05-17T23:40:09Z","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 review the numerical techniques for ideal and non-ideal magneto-hydrodynamics (MHD) used in the context of star formation simulations. We outline the specific challenges offered by modeling star forming environments, which are dominated by supersonic and super-Alfvenic turbulence in a radiative, self-gravitating fluid. These conditions are rather unique in physics and engineering and pose particularly severe restrictions on the robustness and accuracy of numerical codes. One striking aspect is the formation of collapsing fluid elements leading to the formation of singularities that represen","authors_text":"Benoit Commercon, Romain Teyssier","cross_cats":["astro-ph.GA","astro-ph.SR"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-19T15:12:30Z","title":"Numerical Methods for Simulating Star Formation"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.08542","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":"sha256:88586dd9e96ab372c36dd7d67d47ac5b1257429492db556fa368f31eb56daa39","target":"record","created_at":"2026-05-17T23:40:09Z","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":"9442012a386024e86474d1ab1ee7664f54bb6ef058d24e6ed0c79d23d93c0a06","cross_cats_sorted":["astro-ph.GA","astro-ph.SR"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-19T15:12:30Z","title_canon_sha256":"c56795f8e5c3648f5d2585cefbc3c00096234cb9bd5d7b9c95cb625042bbeaab"},"schema_version":"1.0","source":{"id":"1907.08542","kind":"arxiv","version":1}},"canonical_sha256":"863917f8493f91b410fdef2b7eb62a834fdcb5aa58d06e737650312c637a3cfe","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"863917f8493f91b410fdef2b7eb62a834fdcb5aa58d06e737650312c637a3cfe","first_computed_at":"2026-05-17T23:40:09.471404Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:40:09.471404Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"gMl4pGVHcWSRBOi9TOhO7b+//cyCWuWXhsPwzzfbXKY1nqZZz8C5choFpa2c5FQuWvCChYXAe6kxbnrrfDf7DA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:40:09.475086Z","signed_message":"canonical_sha256_bytes"},"source_id":"1907.08542","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:88586dd9e96ab372c36dd7d67d47ac5b1257429492db556fa368f31eb56daa39","sha256:3499b4389ba657e1d9f6799589060cdfb5097435661e27a92e58b08ffab4aca1"],"state_sha256":"36020ab53fc99fda709e3dca89c5b6fa335689e768bf287a1c755451384c76cc"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"udckbVSOGjQ5JYMYUBngKawQmypreIMu9SR5dg6RS7CJp0xZ6xhTVsdbr1++jiIaqAua1DRVqnPdbTgJiqGXAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-07T09:36:04.944294Z","bundle_sha256":"94f1ac2be063d466c0391548af02d3c0d91833f835400a7e0fd80bb48c43d7ce"}}