{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2000:PM7M33LJKWKK4GLLXK355WHU47","short_pith_number":"pith:PM7M33LJ","canonical_record":{"source":{"id":"astro-ph/0004029","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2000-04-03T23:59:19Z","cross_cats_sorted":[],"title_canon_sha256":"e632f3d7a533edaf49b7d2e39e1fb8477e8211157a2effc2dd2b98cf8717efa0","abstract_canon_sha256":"bb6ad04e46a5106870dc99e1ca225f19433a7b574cebd4e40d99b0b2b9d8fd92"},"schema_version":"1.0"},"canonical_sha256":"7b3ecded695594ae196bbab7ded8f4e7ce97008c72b71f73ae071ddbf95e617b","source":{"kind":"arxiv","id":"astro-ph/0004029","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0004029","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0004029v1","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0004029","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"pith_short_12","alias_value":"PM7M33LJKWKK","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_16","alias_value":"PM7M33LJKWKK4GLL","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_8","alias_value":"PM7M33LJ","created_at":"2026-05-18T12:25:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2000:PM7M33LJKWKK4GLLXK355WHU47","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0004029","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2000-04-03T23:59:19Z","cross_cats_sorted":[],"title_canon_sha256":"e632f3d7a533edaf49b7d2e39e1fb8477e8211157a2effc2dd2b98cf8717efa0","abstract_canon_sha256":"bb6ad04e46a5106870dc99e1ca225f19433a7b574cebd4e40d99b0b2b9d8fd92"},"schema_version":"1.0"},"canonical_sha256":"7b3ecded695594ae196bbab7ded8f4e7ce97008c72b71f73ae071ddbf95e617b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:21:57.186266Z","signature_b64":"4lw0hs2Z+e+0+QovNiHm6wCn2iajM72oOl44/sxLnD3OsqniCNY9yVwCEA8vAYMYxtbo3b9Y99qs40KE8TCaCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7b3ecded695594ae196bbab7ded8f4e7ce97008c72b71f73ae071ddbf95e617b","last_reissued_at":"2026-05-18T01:21:57.185631Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:21:57.185631Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0004029","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":"2026-05-18T01:21:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uX123MBxu1UwzlPpfzJa4elD6oCzxSnH8oYrPKaK3kZbA+S0+DDu5h5eR5pREM22ujRW19FhQm9MdEey0czcAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-30T16:59:35.436603Z"},"content_sha256":"e9a2da63f403b3adb6705e13ba1669971acbe3dfcb3784ba0c56c781f8928c7b","schema_version":"1.0","event_id":"sha256:e9a2da63f403b3adb6705e13ba1669971acbe3dfcb3784ba0c56c781f8928c7b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2000:PM7M33LJKWKK4GLLXK355WHU47","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The effects of a Variable IMF on the Chemical Evolution of the Galaxy","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Cristina Chiappini (1), Francesca Matteucci (2) ((1) Columbia University, Italy), USA (2) Universita di Trieste","submitted_at":"2000-04-03T23:59:19Z","abstract_excerpt":"In this work we explore the effects of adopting an initial mass function (IMF) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the formation of the Galaxy. We study the effects on such a model of different IMFs. First, we use a theoretical one based on the statistical description of the density field arising from random motions in the gas. This IMF is a function of time as it depends on physical conditions of the site of star formation. We also investigate the behaviour of the model pre"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0004029","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":"2026-05-18T01:21:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rbBD2vm10kxKIeK1PnIamYP8wsGNinnlU8vECewPxOSVoxYjx6fvPx79ukCKMPwql9K+EUWlUqdKo/LLikbHBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-30T16:59:35.437335Z"},"content_sha256":"d07a9fc8b9cf6d968b4dac99393ab46b4427fbffde252f456bdeb60dba1e8fc2","schema_version":"1.0","event_id":"sha256:d07a9fc8b9cf6d968b4dac99393ab46b4427fbffde252f456bdeb60dba1e8fc2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PM7M33LJKWKK4GLLXK355WHU47/bundle.json","state_url":"https://pith.science/pith/PM7M33LJKWKK4GLLXK355WHU47/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PM7M33LJKWKK4GLLXK355WHU47/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":"2026-06-30T16:59:35Z","links":{"resolver":"https://pith.science/pith/PM7M33LJKWKK4GLLXK355WHU47","bundle":"https://pith.science/pith/PM7M33LJKWKK4GLLXK355WHU47/bundle.json","state":"https://pith.science/pith/PM7M33LJKWKK4GLLXK355WHU47/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PM7M33LJKWKK4GLLXK355WHU47/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2000:PM7M33LJKWKK4GLLXK355WHU47","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":"bb6ad04e46a5106870dc99e1ca225f19433a7b574cebd4e40d99b0b2b9d8fd92","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2000-04-03T23:59:19Z","title_canon_sha256":"e632f3d7a533edaf49b7d2e39e1fb8477e8211157a2effc2dd2b98cf8717efa0"},"schema_version":"1.0","source":{"id":"astro-ph/0004029","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0004029","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0004029v1","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0004029","created_at":"2026-05-18T01:21:57Z"},{"alias_kind":"pith_short_12","alias_value":"PM7M33LJKWKK","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_16","alias_value":"PM7M33LJKWKK4GLL","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_8","alias_value":"PM7M33LJ","created_at":"2026-05-18T12:25:50Z"}],"graph_snapshots":[{"event_id":"sha256:d07a9fc8b9cf6d968b4dac99393ab46b4427fbffde252f456bdeb60dba1e8fc2","target":"graph","created_at":"2026-05-18T01:21:57Z","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":"In this work we explore the effects of adopting an initial mass function (IMF) variable in time on the chemical evolution of the Galaxy. In order to do that we adopt a chemical evolution model which assumes two main infall episodes for the formation of the Galaxy. We study the effects on such a model of different IMFs. First, we use a theoretical one based on the statistical description of the density field arising from random motions in the gas. This IMF is a function of time as it depends on physical conditions of the site of star formation. We also investigate the behaviour of the model pre","authors_text":"Cristina Chiappini (1), Francesca Matteucci (2) ((1) Columbia University, Italy), USA (2) Universita di Trieste","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2000-04-03T23:59:19Z","title":"The effects of a Variable IMF on the Chemical Evolution of the Galaxy"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0004029","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:e9a2da63f403b3adb6705e13ba1669971acbe3dfcb3784ba0c56c781f8928c7b","target":"record","created_at":"2026-05-18T01:21:57Z","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":"bb6ad04e46a5106870dc99e1ca225f19433a7b574cebd4e40d99b0b2b9d8fd92","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2000-04-03T23:59:19Z","title_canon_sha256":"e632f3d7a533edaf49b7d2e39e1fb8477e8211157a2effc2dd2b98cf8717efa0"},"schema_version":"1.0","source":{"id":"astro-ph/0004029","kind":"arxiv","version":1}},"canonical_sha256":"7b3ecded695594ae196bbab7ded8f4e7ce97008c72b71f73ae071ddbf95e617b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7b3ecded695594ae196bbab7ded8f4e7ce97008c72b71f73ae071ddbf95e617b","first_computed_at":"2026-05-18T01:21:57.185631Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:21:57.185631Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"4lw0hs2Z+e+0+QovNiHm6wCn2iajM72oOl44/sxLnD3OsqniCNY9yVwCEA8vAYMYxtbo3b9Y99qs40KE8TCaCQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:21:57.186266Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0004029","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e9a2da63f403b3adb6705e13ba1669971acbe3dfcb3784ba0c56c781f8928c7b","sha256:d07a9fc8b9cf6d968b4dac99393ab46b4427fbffde252f456bdeb60dba1e8fc2"],"state_sha256":"a10e2f4c1664906dac01633238be0dd691378878e1c1559a5ada585c85071cae"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"BTPLnl2ok7+N4Y5fH8CS7j194OgkgdVzWUZaC+QAO/ut0q/ACXIsJ45ygDeOrl9+Gsg1axmQzBrMUF8FFVH+BQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-30T16:59:35.440215Z","bundle_sha256":"e8c8668e6498b46a629c74385d686cdaed4ca3ecd4caa6fd7ac02ab5221abeb1"}}