{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2010:CGDNKC72RIEATRPDLTGCMPBIB7","short_pith_number":"pith:CGDNKC72","canonical_record":{"source":{"id":"1004.2378","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-14T12:13:02Z","cross_cats_sorted":[],"title_canon_sha256":"3f7abb47a06e022312fefd7d9f547493fad7f52af542e20dbe963d0ba612f91d","abstract_canon_sha256":"0f826e5727042e0be0aad73c20e07c72995ed016523a7986b66d975fe2b43da1"},"schema_version":"1.0"},"canonical_sha256":"1186d50bfa8a0809c5e35ccc263c280feb5666a0e14e897e7f4e860c9bc79236","source":{"kind":"arxiv","id":"1004.2378","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1004.2378","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"arxiv_version","alias_value":"1004.2378v1","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1004.2378","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"pith_short_12","alias_value":"CGDNKC72RIEA","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_16","alias_value":"CGDNKC72RIEATRPD","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_8","alias_value":"CGDNKC72","created_at":"2026-05-18T12:26:05Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2010:CGDNKC72RIEATRPDLTGCMPBIB7","target":"record","payload":{"canonical_record":{"source":{"id":"1004.2378","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-14T12:13:02Z","cross_cats_sorted":[],"title_canon_sha256":"3f7abb47a06e022312fefd7d9f547493fad7f52af542e20dbe963d0ba612f91d","abstract_canon_sha256":"0f826e5727042e0be0aad73c20e07c72995ed016523a7986b66d975fe2b43da1"},"schema_version":"1.0"},"canonical_sha256":"1186d50bfa8a0809c5e35ccc263c280feb5666a0e14e897e7f4e860c9bc79236","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:08:05.759445Z","signature_b64":"i5YaPEtCGug6MKmT8bs/X1D+r/roG55lqHYlqg7qRKw5tSv2/bGGIVfX47ApqAnnZ4iuw0/HLRdbJoDkO+LfAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1186d50bfa8a0809c5e35ccc263c280feb5666a0e14e897e7f4e860c9bc79236","last_reissued_at":"2026-05-18T02:08:05.758654Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:08:05.758654Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1004.2378","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":"2026-05-18T02:08:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MUxq+LkYfcgz6Zh8nZGTJkb8U4ELDZKqijHir+s2kGsNT0QaMpAO3RkrUA6VWtHDmyZCUQBYzPQWWFJ08r0WAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T21:03:55.990271Z"},"content_sha256":"378e98fffdf529597ae270c03fc263608bf2b07ecfc031dfd0227cbe52a6ab5e","schema_version":"1.0","event_id":"sha256:378e98fffdf529597ae270c03fc263608bf2b07ecfc031dfd0227cbe52a6ab5e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2010:CGDNKC72RIEATRPDLTGCMPBIB7","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Luminous Red Galaxies in Simulations: Cosmic Chronometers?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"A. L. Ratsimbazafy, C. M. Cress, E. A. Olivier, K. J. van der Heyden, S-L. Blyth, S. M. Crawford","submitted_at":"2010-04-14T12:13:02Z","abstract_excerpt":"There have been a number of attempts to measure the expansion rate of the universe at high redshift using Luminous Red Galaxies (LRGs) as \"chronometers\". The method generally assumes that stars in LRGs are all formed at the same time. In this paper, we quantify the uncertainties on the measurement of H(z) which arise when one considers more realistic, extended star formation histories. In selecting galaxies from the Millennium Simulation for this study, we show that using rest-frame criteria significantly improves the homogeneity of the sample and that H(z) can be recovered to within 3% at z~0"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1004.2378","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":"2026-05-18T02:08:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WELMIe4zpFAr2hNCBGDgDRg/K+qBiRKv27tLblDwQ0BWPAw62hr5+S69I+GXD3nhfKrTcpkIfJF5BFCZXdbGBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T21:03:55.990950Z"},"content_sha256":"16afa556cc668c5a397249d16b57819c7a36210aac1861135d60ad09df870ebc","schema_version":"1.0","event_id":"sha256:16afa556cc668c5a397249d16b57819c7a36210aac1861135d60ad09df870ebc"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/CGDNKC72RIEATRPDLTGCMPBIB7/bundle.json","state_url":"https://pith.science/pith/CGDNKC72RIEATRPDLTGCMPBIB7/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/CGDNKC72RIEATRPDLTGCMPBIB7/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":"2026-05-27T21:03:55Z","links":{"resolver":"https://pith.science/pith/CGDNKC72RIEATRPDLTGCMPBIB7","bundle":"https://pith.science/pith/CGDNKC72RIEATRPDLTGCMPBIB7/bundle.json","state":"https://pith.science/pith/CGDNKC72RIEATRPDLTGCMPBIB7/state.json","well_known_bundle":"https://pith.science/.well-known/pith/CGDNKC72RIEATRPDLTGCMPBIB7/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:CGDNKC72RIEATRPDLTGCMPBIB7","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":"0f826e5727042e0be0aad73c20e07c72995ed016523a7986b66d975fe2b43da1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-14T12:13:02Z","title_canon_sha256":"3f7abb47a06e022312fefd7d9f547493fad7f52af542e20dbe963d0ba612f91d"},"schema_version":"1.0","source":{"id":"1004.2378","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1004.2378","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"arxiv_version","alias_value":"1004.2378v1","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1004.2378","created_at":"2026-05-18T02:08:05Z"},{"alias_kind":"pith_short_12","alias_value":"CGDNKC72RIEA","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_16","alias_value":"CGDNKC72RIEATRPD","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_8","alias_value":"CGDNKC72","created_at":"2026-05-18T12:26:05Z"}],"graph_snapshots":[{"event_id":"sha256:16afa556cc668c5a397249d16b57819c7a36210aac1861135d60ad09df870ebc","target":"graph","created_at":"2026-05-18T02:08:05Z","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":"There have been a number of attempts to measure the expansion rate of the universe at high redshift using Luminous Red Galaxies (LRGs) as \"chronometers\". The method generally assumes that stars in LRGs are all formed at the same time. In this paper, we quantify the uncertainties on the measurement of H(z) which arise when one considers more realistic, extended star formation histories. In selecting galaxies from the Millennium Simulation for this study, we show that using rest-frame criteria significantly improves the homogeneity of the sample and that H(z) can be recovered to within 3% at z~0","authors_text":"A. L. Ratsimbazafy, C. M. Cress, E. A. Olivier, K. J. van der Heyden, S-L. Blyth, S. M. Crawford","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-14T12:13:02Z","title":"Luminous Red Galaxies in Simulations: Cosmic Chronometers?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1004.2378","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":"sha256:378e98fffdf529597ae270c03fc263608bf2b07ecfc031dfd0227cbe52a6ab5e","target":"record","created_at":"2026-05-18T02:08:05Z","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":"0f826e5727042e0be0aad73c20e07c72995ed016523a7986b66d975fe2b43da1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-14T12:13:02Z","title_canon_sha256":"3f7abb47a06e022312fefd7d9f547493fad7f52af542e20dbe963d0ba612f91d"},"schema_version":"1.0","source":{"id":"1004.2378","kind":"arxiv","version":1}},"canonical_sha256":"1186d50bfa8a0809c5e35ccc263c280feb5666a0e14e897e7f4e860c9bc79236","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1186d50bfa8a0809c5e35ccc263c280feb5666a0e14e897e7f4e860c9bc79236","first_computed_at":"2026-05-18T02:08:05.758654Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:08:05.758654Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"i5YaPEtCGug6MKmT8bs/X1D+r/roG55lqHYlqg7qRKw5tSv2/bGGIVfX47ApqAnnZ4iuw0/HLRdbJoDkO+LfAQ==","signature_status":"signed_v1","signed_at":"2026-05-18T02:08:05.759445Z","signed_message":"canonical_sha256_bytes"},"source_id":"1004.2378","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:378e98fffdf529597ae270c03fc263608bf2b07ecfc031dfd0227cbe52a6ab5e","sha256:16afa556cc668c5a397249d16b57819c7a36210aac1861135d60ad09df870ebc"],"state_sha256":"81c4a51a70f3630e239ddbc4d8fa188611473bd746b85cd0704d897522d420c3"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pPzAerJxBHfhEX0+Lk4GGaI/xqMo8Pjj32UOa73AHuXR05l9sqW/zjL72EegCTC9mHU9zoJWBcLmd8h1XqWlCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T21:03:55.994373Z","bundle_sha256":"ca116eb2ae9cef1fa523d335892d98bdd97dfd65aba0eebc8fd64cb7a6b6e372"}}