{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:5YGAA3C44ZL2ASJ6R5IZ3LYOIS","short_pith_number":"pith:5YGAA3C4","canonical_record":{"source":{"id":"1503.05969","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-20T00:00:20Z","cross_cats_sorted":[],"title_canon_sha256":"4d27db1fc0f43f00db3a1678c6ef48a478ad9992996baaaf3cd6004001c0c12b","abstract_canon_sha256":"b323a570bd8999d0242bd42738cd88523925c5d64c0abcdf5332a7c030245bdd"},"schema_version":"1.0"},"canonical_sha256":"ee0c006c5ce657a0493e8f519daf0e44ae383836dac61fe74b4297ef0ed2351e","source":{"kind":"arxiv","id":"1503.05969","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.05969","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"arxiv_version","alias_value":"1503.05969v2","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.05969","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"pith_short_12","alias_value":"5YGAA3C44ZL2","created_at":"2026-05-18T12:29:07Z"},{"alias_kind":"pith_short_16","alias_value":"5YGAA3C44ZL2ASJ6","created_at":"2026-05-18T12:29:07Z"},{"alias_kind":"pith_short_8","alias_value":"5YGAA3C4","created_at":"2026-05-18T12:29:07Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:5YGAA3C44ZL2ASJ6R5IZ3LYOIS","target":"record","payload":{"canonical_record":{"source":{"id":"1503.05969","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-20T00:00:20Z","cross_cats_sorted":[],"title_canon_sha256":"4d27db1fc0f43f00db3a1678c6ef48a478ad9992996baaaf3cd6004001c0c12b","abstract_canon_sha256":"b323a570bd8999d0242bd42738cd88523925c5d64c0abcdf5332a7c030245bdd"},"schema_version":"1.0"},"canonical_sha256":"ee0c006c5ce657a0493e8f519daf0e44ae383836dac61fe74b4297ef0ed2351e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:23:08.600838Z","signature_b64":"SfXCBHMYq/av21wYP7mDWka+ttp/NIFBdMq/pNXiDRJsxTahOW09lEEppv1C/eIODSNIFj9w07oLPE+T+1f7BA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ee0c006c5ce657a0493e8f519daf0e44ae383836dac61fe74b4297ef0ed2351e","last_reissued_at":"2026-05-18T01:23:08.600403Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:23:08.600403Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1503.05969","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:23:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FFLKrlS8ngicbmZ33L4B+pcYzuT9JUBU/FaUo/962vL9YRtBJn1PiEPddfTl11kAY/Kds8dqdAnwz5sfvHN/Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T04:25:16.109330Z"},"content_sha256":"e37c7315053494c51e6e9700088a100361bb204fe501893c23560904216c6fe5","schema_version":"1.0","event_id":"sha256:e37c7315053494c51e6e9700088a100361bb204fe501893c23560904216c6fe5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:5YGAA3C44ZL2ASJ6R5IZ3LYOIS","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Convergence of Particle-in-Cell Schemes for Cosmological Dark Matter Simulations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Andrew Myers, Brian Van Straalen, Phillip Colella","submitted_at":"2015-03-20T00:00:20Z","abstract_excerpt":"Particle methods are a ubiquitous tool for solving the Vlasov-Poisson equation in comoving coordinates, which is used to model the gravitational evolution of dark matter in an expanding universe. However, these methods are known to produce poor results on idealized test problems, particularly at late times, after the particle trajectories have crossed. To investigate this, we have performed a series of one- and two-dimensional \"Zel'dovich Pancake\" calculations using the popular Particle-in-Cell (PIC) method. We find that PIC can indeed converge on these problems provided the following modifica"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.05969","kind":"arxiv","version":2},"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":"2026-05-18T01:23:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ymO+yKSQZWjOOY8B1wXLqVtglKe4+fG+hkA9xHZ6UooZSdjXE7p1DB/g/G4y4gCiZmILk4F/n0xoPV5DSpUXDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T04:25:16.110075Z"},"content_sha256":"ab5bb1bfde321f5ee8db465c89ef629defbf15f0bcc896f57c5e2abafbd5b47f","schema_version":"1.0","event_id":"sha256:ab5bb1bfde321f5ee8db465c89ef629defbf15f0bcc896f57c5e2abafbd5b47f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/bundle.json","state_url":"https://pith.science/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/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":"2026-05-25T04:25:16Z","links":{"resolver":"https://pith.science/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS","bundle":"https://pith.science/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/bundle.json","state":"https://pith.science/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/state.json","well_known_bundle":"https://pith.science/.well-known/pith/5YGAA3C44ZL2ASJ6R5IZ3LYOIS/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:5YGAA3C44ZL2ASJ6R5IZ3LYOIS","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":"b323a570bd8999d0242bd42738cd88523925c5d64c0abcdf5332a7c030245bdd","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-20T00:00:20Z","title_canon_sha256":"4d27db1fc0f43f00db3a1678c6ef48a478ad9992996baaaf3cd6004001c0c12b"},"schema_version":"1.0","source":{"id":"1503.05969","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.05969","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"arxiv_version","alias_value":"1503.05969v2","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.05969","created_at":"2026-05-18T01:23:08Z"},{"alias_kind":"pith_short_12","alias_value":"5YGAA3C44ZL2","created_at":"2026-05-18T12:29:07Z"},{"alias_kind":"pith_short_16","alias_value":"5YGAA3C44ZL2ASJ6","created_at":"2026-05-18T12:29:07Z"},{"alias_kind":"pith_short_8","alias_value":"5YGAA3C4","created_at":"2026-05-18T12:29:07Z"}],"graph_snapshots":[{"event_id":"sha256:ab5bb1bfde321f5ee8db465c89ef629defbf15f0bcc896f57c5e2abafbd5b47f","target":"graph","created_at":"2026-05-18T01:23:08Z","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":"Particle methods are a ubiquitous tool for solving the Vlasov-Poisson equation in comoving coordinates, which is used to model the gravitational evolution of dark matter in an expanding universe. However, these methods are known to produce poor results on idealized test problems, particularly at late times, after the particle trajectories have crossed. To investigate this, we have performed a series of one- and two-dimensional \"Zel'dovich Pancake\" calculations using the popular Particle-in-Cell (PIC) method. We find that PIC can indeed converge on these problems provided the following modifica","authors_text":"Andrew Myers, Brian Van Straalen, Phillip Colella","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-20T00:00:20Z","title":"The Convergence of Particle-in-Cell Schemes for Cosmological Dark Matter Simulations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.05969","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:e37c7315053494c51e6e9700088a100361bb204fe501893c23560904216c6fe5","target":"record","created_at":"2026-05-18T01:23:08Z","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":"b323a570bd8999d0242bd42738cd88523925c5d64c0abcdf5332a7c030245bdd","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-20T00:00:20Z","title_canon_sha256":"4d27db1fc0f43f00db3a1678c6ef48a478ad9992996baaaf3cd6004001c0c12b"},"schema_version":"1.0","source":{"id":"1503.05969","kind":"arxiv","version":2}},"canonical_sha256":"ee0c006c5ce657a0493e8f519daf0e44ae383836dac61fe74b4297ef0ed2351e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ee0c006c5ce657a0493e8f519daf0e44ae383836dac61fe74b4297ef0ed2351e","first_computed_at":"2026-05-18T01:23:08.600403Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:23:08.600403Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"SfXCBHMYq/av21wYP7mDWka+ttp/NIFBdMq/pNXiDRJsxTahOW09lEEppv1C/eIODSNIFj9w07oLPE+T+1f7BA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:23:08.600838Z","signed_message":"canonical_sha256_bytes"},"source_id":"1503.05969","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e37c7315053494c51e6e9700088a100361bb204fe501893c23560904216c6fe5","sha256:ab5bb1bfde321f5ee8db465c89ef629defbf15f0bcc896f57c5e2abafbd5b47f"],"state_sha256":"f3d6594bd7c1a0bf858d5ffa94a15a5d9099f92707cc61c3fcc342d4453795f4"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ug2WWKkdZ0QlrFuVCQzydKzyGJA+1x/VR+xeIDIb1q0Pc+oKh0YVx8pAv5xqWSu+/qfGdznIFXlwqxYENhcECQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T04:25:16.115453Z","bundle_sha256":"027134197c7731fc0fc158774f5d8a7ea9ea6082fee95227cac59b062a982ea8"}}