{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:1997:7KYTVA2XGJ7FU6CZJSREJIAO5U","short_pith_number":"pith:7KYTVA2X","canonical_record":{"source":{"id":"cond-mat/9712134","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"cond-mat","submitted_at":"1997-12-12T09:29:56Z","cross_cats_sorted":[],"title_canon_sha256":"daab3f81cb6be8bbd3a25ea34f990602b10224138bac5a00c5cf0f89c0dfebd5","abstract_canon_sha256":"7d29420f8aa3ee5128d8f876cc340565c242a645253953db0bb87381775c57cc"},"schema_version":"1.0"},"canonical_sha256":"fab13a8357327e5a78594ca244a00eed3af1c2f1b9a21a548343f7f64ec7791e","source":{"kind":"arxiv","id":"cond-mat/9712134","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"cond-mat/9712134","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"arxiv_version","alias_value":"cond-mat/9712134v1","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.cond-mat/9712134","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_12","alias_value":"7KYTVA2XGJ7F","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_16","alias_value":"7KYTVA2XGJ7FU6CZ","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_8","alias_value":"7KYTVA2X","created_at":"2026-07-04T16:04:27Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:1997:7KYTVA2XGJ7FU6CZJSREJIAO5U","target":"record","payload":{"canonical_record":{"source":{"id":"cond-mat/9712134","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"cond-mat","submitted_at":"1997-12-12T09:29:56Z","cross_cats_sorted":[],"title_canon_sha256":"daab3f81cb6be8bbd3a25ea34f990602b10224138bac5a00c5cf0f89c0dfebd5","abstract_canon_sha256":"7d29420f8aa3ee5128d8f876cc340565c242a645253953db0bb87381775c57cc"},"schema_version":"1.0"},"canonical_sha256":"fab13a8357327e5a78594ca244a00eed3af1c2f1b9a21a548343f7f64ec7791e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T16:04:27.734398Z","signature_b64":"SNP32SqBUohf+mYx8WO70gZCCUIUsZMmYroXgW3p+uXc8qzMB0mBs4yt4g/sxzs8KHEzbi1tvracPIjICEDrDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fab13a8357327e5a78594ca244a00eed3af1c2f1b9a21a548343f7f64ec7791e","last_reissued_at":"2026-07-04T16:04:27.734024Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T16:04:27.734024Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"cond-mat/9712134","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":"2026-07-04T16:04:27Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Rxwc9kgqRuhLz+VrOsR+pVTHbZ8z0yYO7Zok0aNdZQcl0fUrWouVbjF0+PQ0Ydct3vXl1zxrTmdvZh2jXEPZAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T12:32:13.952818Z"},"content_sha256":"fba6752dc6d47d3553ededcfd079d9c7479bca937e3a61eac62af3df3d0a1d7f","schema_version":"1.0","event_id":"sha256:fba6752dc6d47d3553ededcfd079d9c7479bca937e3a61eac62af3df3d0a1d7f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:1997:7KYTVA2XGJ7FU6CZJSREJIAO5U","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"DMRG study of the spin gap in a one dimensional Hubbard model: effect of the distant transfer and exchange coupling","license":"","headline":"","cross_cats":[],"primary_cat":"cond-mat","authors_text":"Hideo Aoki, Kazuhiko Kuroki, Michele Fabrizio, Ryotaro Arita","submitted_at":"1997-12-12T09:29:56Z","abstract_excerpt":"The spin gap of a one-dimensional repulsive Hubbard model is numerically calculated with the density matrix renormalization group, with a special emphasis on the effect of a next-nearest neighbor hopping (t') and the nearest-neighbor ferromagnetic exchange (J) interaction. At half-filling, a significant spin gap opens if |t'| \\simeq |t| and J=0, in agreement with the weak coupling theory, while the gap is strongly suppressed by the introduction of J. On the other hand, the quarter-filled system has very small spin gaps regardless of the values of t' and J. Implications for the CuO_2 chain in S"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9712134","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/cond-mat/9712134/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-04T16:04:27Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yRR0lbcNqucYQP+I251oKYMqAT8feKaPM2DiL7YrRATzXBGJQOLZU3UwyANkuQMVCszSzx1Qk1gohdaQfrngAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T12:32:13.953197Z"},"content_sha256":"049bdbe3563b2dc15c63084703c63133ed801994342849094ff5a1f48c9d806c","schema_version":"1.0","event_id":"sha256:049bdbe3563b2dc15c63084703c63133ed801994342849094ff5a1f48c9d806c"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/bundle.json","state_url":"https://pith.science/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/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":"2026-07-07T12:32:13Z","links":{"resolver":"https://pith.science/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U","bundle":"https://pith.science/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/bundle.json","state":"https://pith.science/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7KYTVA2XGJ7FU6CZJSREJIAO5U/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1997:7KYTVA2XGJ7FU6CZJSREJIAO5U","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":"7d29420f8aa3ee5128d8f876cc340565c242a645253953db0bb87381775c57cc","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat","submitted_at":"1997-12-12T09:29:56Z","title_canon_sha256":"daab3f81cb6be8bbd3a25ea34f990602b10224138bac5a00c5cf0f89c0dfebd5"},"schema_version":"1.0","source":{"id":"cond-mat/9712134","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"cond-mat/9712134","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"arxiv_version","alias_value":"cond-mat/9712134v1","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.cond-mat/9712134","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_12","alias_value":"7KYTVA2XGJ7F","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_16","alias_value":"7KYTVA2XGJ7FU6CZ","created_at":"2026-07-04T16:04:27Z"},{"alias_kind":"pith_short_8","alias_value":"7KYTVA2X","created_at":"2026-07-04T16:04:27Z"}],"graph_snapshots":[{"event_id":"sha256:049bdbe3563b2dc15c63084703c63133ed801994342849094ff5a1f48c9d806c","target":"graph","created_at":"2026-07-04T16:04:27Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/cond-mat/9712134/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The spin gap of a one-dimensional repulsive Hubbard model is numerically calculated with the density matrix renormalization group, with a special emphasis on the effect of a next-nearest neighbor hopping (t') and the nearest-neighbor ferromagnetic exchange (J) interaction. At half-filling, a significant spin gap opens if |t'| \\simeq |t| and J=0, in agreement with the weak coupling theory, while the gap is strongly suppressed by the introduction of J. On the other hand, the quarter-filled system has very small spin gaps regardless of the values of t' and J. Implications for the CuO_2 chain in S","authors_text":"Hideo Aoki, Kazuhiko Kuroki, Michele Fabrizio, Ryotaro Arita","cross_cats":[],"headline":"","license":"","primary_cat":"cond-mat","submitted_at":"1997-12-12T09:29:56Z","title":"DMRG study of the spin gap in a one dimensional Hubbard model: effect of the distant transfer and exchange coupling"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9712134","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:fba6752dc6d47d3553ededcfd079d9c7479bca937e3a61eac62af3df3d0a1d7f","target":"record","created_at":"2026-07-04T16:04:27Z","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":"7d29420f8aa3ee5128d8f876cc340565c242a645253953db0bb87381775c57cc","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat","submitted_at":"1997-12-12T09:29:56Z","title_canon_sha256":"daab3f81cb6be8bbd3a25ea34f990602b10224138bac5a00c5cf0f89c0dfebd5"},"schema_version":"1.0","source":{"id":"cond-mat/9712134","kind":"arxiv","version":1}},"canonical_sha256":"fab13a8357327e5a78594ca244a00eed3af1c2f1b9a21a548343f7f64ec7791e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fab13a8357327e5a78594ca244a00eed3af1c2f1b9a21a548343f7f64ec7791e","first_computed_at":"2026-07-04T16:04:27.734024Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T16:04:27.734024Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"SNP32SqBUohf+mYx8WO70gZCCUIUsZMmYroXgW3p+uXc8qzMB0mBs4yt4g/sxzs8KHEzbi1tvracPIjICEDrDg==","signature_status":"signed_v1","signed_at":"2026-07-04T16:04:27.734398Z","signed_message":"canonical_sha256_bytes"},"source_id":"cond-mat/9712134","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:fba6752dc6d47d3553ededcfd079d9c7479bca937e3a61eac62af3df3d0a1d7f","sha256:049bdbe3563b2dc15c63084703c63133ed801994342849094ff5a1f48c9d806c"],"state_sha256":"7484501051751a16ae1df902564f912965ed2dd07a313ed5658ef87fd3205e86"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"003l1DXE/oq8u0clNeUby8IkXfCHNNGj/1LmQuaYf9/rUMi0s4+5EOlb7RLRnJ3df3uxDjWwrH/ZZiiacmjpCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-07T12:32:13.955192Z","bundle_sha256":"2022caf625a2e546fd47c41b7bc529a9120c99bed7a55526190ff4d29bc9a941"}}