{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:XOGFX7XZG5QSSUV2BJ4PBOUWSZ","short_pith_number":"pith:XOGFX7XZ","canonical_record":{"source":{"id":"1503.02689","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-09T20:51:25Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"8cccbf703127750c4356a27f71b7618d405b0655f291c9b2c79e0851d8b53235","abstract_canon_sha256":"4db65102a66d28313c4c3d27f5e58e4a8ff92163ba1ac57fe7819a377522de9d"},"schema_version":"1.0"},"canonical_sha256":"bb8c5bfef937612952ba0a78f0ba96965f35d19137f7184d48b20d8d3ba1bed7","source":{"kind":"arxiv","id":"1503.02689","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.02689","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"arxiv_version","alias_value":"1503.02689v1","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.02689","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"pith_short_12","alias_value":"XOGFX7XZG5QS","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_16","alias_value":"XOGFX7XZG5QSSUV2","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_8","alias_value":"XOGFX7XZ","created_at":"2026-05-18T12:29:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:XOGFX7XZG5QSSUV2BJ4PBOUWSZ","target":"record","payload":{"canonical_record":{"source":{"id":"1503.02689","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-09T20:51:25Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"8cccbf703127750c4356a27f71b7618d405b0655f291c9b2c79e0851d8b53235","abstract_canon_sha256":"4db65102a66d28313c4c3d27f5e58e4a8ff92163ba1ac57fe7819a377522de9d"},"schema_version":"1.0"},"canonical_sha256":"bb8c5bfef937612952ba0a78f0ba96965f35d19137f7184d48b20d8d3ba1bed7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:20:11.972060Z","signature_b64":"lgP54jc/2oyCPhMuCBh1ZlWJuHcBDIURJLBnodBHz/Br6VL1eyywpk+LgmOmnwd9AdA0wH2T8G+MaNheWhghAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"bb8c5bfef937612952ba0a78f0ba96965f35d19137f7184d48b20d8d3ba1bed7","last_reissued_at":"2026-05-18T01:20:11.971378Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:20:11.971378Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1503.02689","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":"2026-05-18T01:20:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"EC9jxdze9cgu8mx8lglFDqTamTFcNxm5X1JiRHaf9OlQW+ylWkBQSBQwJd/0et4FMOwsUqWGbO5BEwV3Z1CdBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:43:14.668511Z"},"content_sha256":"1d2f6f4d9c5079e9cade46ce4cf6d7b430ee4a81d390ac3c40385de9b02e557b","schema_version":"1.0","event_id":"sha256:1d2f6f4d9c5079e9cade46ce4cf6d7b430ee4a81d390ac3c40385de9b02e557b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:XOGFX7XZG5QSSUV2BJ4PBOUWSZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Novel Adaptive softening for collisionless N-body simulations: Eliminating spurious halos","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.CO","authors_text":"Alexander Hobbs, Chris Power, Francesca Iannuzzi, Justin Read, Oscar Agertz","submitted_at":"2015-03-09T20:51:25Z","abstract_excerpt":"We describe a NOVel form of Adaptive softening (NovA) for collisionless $N$-body simulations, implemented in the Ramses adaptive mesh refinement code. We introduce a refinement criterion that the particle distribution within each cell be sufficiently isotropic, as measured by its moment of inertia tensor. In this way, collapse is only refined if it occurs along all three axes, ensuring that the softening $\\epsilon$ is always of order twice the largest inter-particle spacing in a cell. This more conservative force softening criterion is designed to minimise spurious two-body effects, while main"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.02689","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":"2026-05-18T01:20:11Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"zCU6G3pgH+0YxIcjxgsqwmZbrCZUKIO7OfWeJPi4wAyafqdbIyrLMJ0YQSleXbtSg07P+Bc0CPOboSV5ukS7Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T14:43:14.668865Z"},"content_sha256":"66374dcb66ff68335c05250352ecd8c09541c57ed34a213500ac1b012908d784","schema_version":"1.0","event_id":"sha256:66374dcb66ff68335c05250352ecd8c09541c57ed34a213500ac1b012908d784"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/bundle.json","state_url":"https://pith.science/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/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":"2026-05-28T14:43:14Z","links":{"resolver":"https://pith.science/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ","bundle":"https://pith.science/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/bundle.json","state":"https://pith.science/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/XOGFX7XZG5QSSUV2BJ4PBOUWSZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:XOGFX7XZG5QSSUV2BJ4PBOUWSZ","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":"4db65102a66d28313c4c3d27f5e58e4a8ff92163ba1ac57fe7819a377522de9d","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-09T20:51:25Z","title_canon_sha256":"8cccbf703127750c4356a27f71b7618d405b0655f291c9b2c79e0851d8b53235"},"schema_version":"1.0","source":{"id":"1503.02689","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.02689","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"arxiv_version","alias_value":"1503.02689v1","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.02689","created_at":"2026-05-18T01:20:11Z"},{"alias_kind":"pith_short_12","alias_value":"XOGFX7XZG5QS","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_16","alias_value":"XOGFX7XZG5QSSUV2","created_at":"2026-05-18T12:29:50Z"},{"alias_kind":"pith_short_8","alias_value":"XOGFX7XZ","created_at":"2026-05-18T12:29:50Z"}],"graph_snapshots":[{"event_id":"sha256:66374dcb66ff68335c05250352ecd8c09541c57ed34a213500ac1b012908d784","target":"graph","created_at":"2026-05-18T01:20:11Z","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 describe a NOVel form of Adaptive softening (NovA) for collisionless $N$-body simulations, implemented in the Ramses adaptive mesh refinement code. We introduce a refinement criterion that the particle distribution within each cell be sufficiently isotropic, as measured by its moment of inertia tensor. In this way, collapse is only refined if it occurs along all three axes, ensuring that the softening $\\epsilon$ is always of order twice the largest inter-particle spacing in a cell. This more conservative force softening criterion is designed to minimise spurious two-body effects, while main","authors_text":"Alexander Hobbs, Chris Power, Francesca Iannuzzi, Justin Read, Oscar Agertz","cross_cats":["astro-ph.IM"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-09T20:51:25Z","title":"Novel Adaptive softening for collisionless N-body simulations: Eliminating spurious halos"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.02689","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":"sha256:1d2f6f4d9c5079e9cade46ce4cf6d7b430ee4a81d390ac3c40385de9b02e557b","target":"record","created_at":"2026-05-18T01:20:11Z","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":"4db65102a66d28313c4c3d27f5e58e4a8ff92163ba1ac57fe7819a377522de9d","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2015-03-09T20:51:25Z","title_canon_sha256":"8cccbf703127750c4356a27f71b7618d405b0655f291c9b2c79e0851d8b53235"},"schema_version":"1.0","source":{"id":"1503.02689","kind":"arxiv","version":1}},"canonical_sha256":"bb8c5bfef937612952ba0a78f0ba96965f35d19137f7184d48b20d8d3ba1bed7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"bb8c5bfef937612952ba0a78f0ba96965f35d19137f7184d48b20d8d3ba1bed7","first_computed_at":"2026-05-18T01:20:11.971378Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:20:11.971378Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lgP54jc/2oyCPhMuCBh1ZlWJuHcBDIURJLBnodBHz/Br6VL1eyywpk+LgmOmnwd9AdA0wH2T8G+MaNheWhghAA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:20:11.972060Z","signed_message":"canonical_sha256_bytes"},"source_id":"1503.02689","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1d2f6f4d9c5079e9cade46ce4cf6d7b430ee4a81d390ac3c40385de9b02e557b","sha256:66374dcb66ff68335c05250352ecd8c09541c57ed34a213500ac1b012908d784"],"state_sha256":"f9067b32abf97d24767cf93044b3ddff22c2bf7054852e413ed049e1d9dd9660"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"utkyi9ldXpzh3l8dgQxY64KUuCaQZNyqe2HOSiKdFqS43wKa/AHZupKskxx1VLBprmUTHD6WU7oCexe94PWYBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T14:43:14.671248Z","bundle_sha256":"77562236cbba243ec896f9700fd1dae946276e83ad13cb9bb60472876975ed4e"}}