{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:CWNUABZBJFQUIDWU4TEEZ5MQEH","short_pith_number":"pith:CWNUABZB","canonical_record":{"source":{"id":"1306.3672","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/3.0/","primary_cat":"astro-ph.EP","submitted_at":"2013-06-16T15:59:52Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"e7341fea1b36229633fb576195a54a4751b80d0670d8437449ea6a6fac68387d","abstract_canon_sha256":"eddd579cc2b8576a6708cc67c2f47ae9ab44b1ccd03a6105ba021827d1a5b53f"},"schema_version":"1.0"},"canonical_sha256":"159b4007214961440ed4e4c84cf59021dbc311e7432e911bec606a41800c1620","source":{"kind":"arxiv","id":"1306.3672","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1306.3672","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"arxiv_version","alias_value":"1306.3672v1","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1306.3672","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"pith_short_12","alias_value":"CWNUABZBJFQU","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_16","alias_value":"CWNUABZBJFQUIDWU","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_8","alias_value":"CWNUABZB","created_at":"2026-05-18T12:27:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:CWNUABZBJFQUIDWU4TEEZ5MQEH","target":"record","payload":{"canonical_record":{"source":{"id":"1306.3672","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/3.0/","primary_cat":"astro-ph.EP","submitted_at":"2013-06-16T15:59:52Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"e7341fea1b36229633fb576195a54a4751b80d0670d8437449ea6a6fac68387d","abstract_canon_sha256":"eddd579cc2b8576a6708cc67c2f47ae9ab44b1ccd03a6105ba021827d1a5b53f"},"schema_version":"1.0"},"canonical_sha256":"159b4007214961440ed4e4c84cf59021dbc311e7432e911bec606a41800c1620","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:16:50.927813Z","signature_b64":"qcLP2duAtHKOuzQfzK5zuLWTQYVxN2IM+j7w4tn6v3m9tX2x94eaNFEwXgRs9pNMT+T2ePSbYAGteg/oltu8DQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"159b4007214961440ed4e4c84cf59021dbc311e7432e911bec606a41800c1620","last_reissued_at":"2026-05-18T03:16:50.927131Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:16:50.927131Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1306.3672","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":"2026-05-18T03:16:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"kuo/zgxPYsivZlXMITuLYeCu/V+tV/rQz6qSwiDNTbZ3NXJLXlZJZOPzfHFnZz090xKR8EopuFibsPU6ygDJAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-23T02:26:07.498453Z"},"content_sha256":"6d9b12e5cebf150feb3caf1e13ea5d495081266899a7cfd311e5167e9d98a494","schema_version":"1.0","event_id":"sha256:6d9b12e5cebf150feb3caf1e13ea5d495081266899a7cfd311e5167e9d98a494"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:CWNUABZBJFQUIDWU4TEEZ5MQEH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Can planetesimals form by collisional fusion?","license":"http://creativecommons.org/licenses/by/3.0/","headline":"","cross_cats":["physics.flu-dyn"],"primary_cat":"astro-ph.EP","authors_text":"2), 3) ((1) NORDITA (2) Yale University (3) Stockholm University), Axel Brandenburg (1, Dhrubaditya Mitra (1), J.S. Wettlaufer (1","submitted_at":"2013-06-16T15:59:52Z","abstract_excerpt":"As a test bed for the growth of protoplanetary bodies in a turbulent circumstellar disk we examine the fate of a boulder using direct numerical simulations of particle seeded gas flowing around it. We provide an accurate description of the flow by imposing no-slip and non-penetrating boundary conditions on the boulder surface using the immersed boundary method pioneered by Peskin (2002). Advected by the turbulent disk flow, the dust grains collide with the boulder and we compute the probability density function (PDF) of the normal component of the collisional velocity. Through this examination"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1306.3672","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":"2026-05-18T03:16:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ArsLJW8YygkJLEvjDZFEFjceuBNCDZyyyqrRN/hQxbfbqJS33fOot/NmuEv1MJx8UYoK7dn//KWX8SlpLZ46Cg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-23T02:26:07.499101Z"},"content_sha256":"9a49868006fa0111b90ff8f3597efbb12d345836a691f0ca09e169ad4242c543","schema_version":"1.0","event_id":"sha256:9a49868006fa0111b90ff8f3597efbb12d345836a691f0ca09e169ad4242c543"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/bundle.json","state_url":"https://pith.science/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/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":"2026-05-23T02:26:07Z","links":{"resolver":"https://pith.science/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH","bundle":"https://pith.science/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/bundle.json","state":"https://pith.science/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/CWNUABZBJFQUIDWU4TEEZ5MQEH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:CWNUABZBJFQUIDWU4TEEZ5MQEH","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":"eddd579cc2b8576a6708cc67c2f47ae9ab44b1ccd03a6105ba021827d1a5b53f","cross_cats_sorted":["physics.flu-dyn"],"license":"http://creativecommons.org/licenses/by/3.0/","primary_cat":"astro-ph.EP","submitted_at":"2013-06-16T15:59:52Z","title_canon_sha256":"e7341fea1b36229633fb576195a54a4751b80d0670d8437449ea6a6fac68387d"},"schema_version":"1.0","source":{"id":"1306.3672","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1306.3672","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"arxiv_version","alias_value":"1306.3672v1","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1306.3672","created_at":"2026-05-18T03:16:50Z"},{"alias_kind":"pith_short_12","alias_value":"CWNUABZBJFQU","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_16","alias_value":"CWNUABZBJFQUIDWU","created_at":"2026-05-18T12:27:40Z"},{"alias_kind":"pith_short_8","alias_value":"CWNUABZB","created_at":"2026-05-18T12:27:40Z"}],"graph_snapshots":[{"event_id":"sha256:9a49868006fa0111b90ff8f3597efbb12d345836a691f0ca09e169ad4242c543","target":"graph","created_at":"2026-05-18T03:16:50Z","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":"As a test bed for the growth of protoplanetary bodies in a turbulent circumstellar disk we examine the fate of a boulder using direct numerical simulations of particle seeded gas flowing around it. We provide an accurate description of the flow by imposing no-slip and non-penetrating boundary conditions on the boulder surface using the immersed boundary method pioneered by Peskin (2002). Advected by the turbulent disk flow, the dust grains collide with the boulder and we compute the probability density function (PDF) of the normal component of the collisional velocity. Through this examination","authors_text":"2), 3) ((1) NORDITA (2) Yale University (3) Stockholm University), Axel Brandenburg (1, Dhrubaditya Mitra (1), J.S. Wettlaufer (1","cross_cats":["physics.flu-dyn"],"headline":"","license":"http://creativecommons.org/licenses/by/3.0/","primary_cat":"astro-ph.EP","submitted_at":"2013-06-16T15:59:52Z","title":"Can planetesimals form by collisional fusion?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1306.3672","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":"sha256:6d9b12e5cebf150feb3caf1e13ea5d495081266899a7cfd311e5167e9d98a494","target":"record","created_at":"2026-05-18T03:16:50Z","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":"eddd579cc2b8576a6708cc67c2f47ae9ab44b1ccd03a6105ba021827d1a5b53f","cross_cats_sorted":["physics.flu-dyn"],"license":"http://creativecommons.org/licenses/by/3.0/","primary_cat":"astro-ph.EP","submitted_at":"2013-06-16T15:59:52Z","title_canon_sha256":"e7341fea1b36229633fb576195a54a4751b80d0670d8437449ea6a6fac68387d"},"schema_version":"1.0","source":{"id":"1306.3672","kind":"arxiv","version":1}},"canonical_sha256":"159b4007214961440ed4e4c84cf59021dbc311e7432e911bec606a41800c1620","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"159b4007214961440ed4e4c84cf59021dbc311e7432e911bec606a41800c1620","first_computed_at":"2026-05-18T03:16:50.927131Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:16:50.927131Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"qcLP2duAtHKOuzQfzK5zuLWTQYVxN2IM+j7w4tn6v3m9tX2x94eaNFEwXgRs9pNMT+T2ePSbYAGteg/oltu8DQ==","signature_status":"signed_v1","signed_at":"2026-05-18T03:16:50.927813Z","signed_message":"canonical_sha256_bytes"},"source_id":"1306.3672","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6d9b12e5cebf150feb3caf1e13ea5d495081266899a7cfd311e5167e9d98a494","sha256:9a49868006fa0111b90ff8f3597efbb12d345836a691f0ca09e169ad4242c543"],"state_sha256":"bd93e00e7624841acc6926017f3b8d79fe5ad7ab5ed1d0b2385cb26ecd987306"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pPEpCWBnr5Rem1oRYD+TAnRS0a8VfL/iHvoh0XWXFnlaiVQzuxxA/euy5Eh+loQLCKV3/H3dnb5ilOBpJNv9Dg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-23T02:26:07.502443Z","bundle_sha256":"7cfb58eb85691923e13b9e395fb5bebef9aa85371aab448854e3d592bc6c4166"}}