{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:7ADKRS4VYWZGQCPAEH4IRISQGR","short_pith_number":"pith:7ADKRS4V","canonical_record":{"source":{"id":"1204.3425","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-04-16T09:48:16Z","cross_cats_sorted":["cond-mat.str-el"],"title_canon_sha256":"adb793b6c1791565256bcc01f2c33f96a730fae3eb44aaa7b0cbab9e043ca263","abstract_canon_sha256":"b4d107aed293f9e0c8293e96ff78133b4d7b3bcadc9b3821fae64ff58cbc69ca"},"schema_version":"1.0"},"canonical_sha256":"f806a8cb95c5b26809e021f888a250347b3d0c940c55afaf9e89d59657fdf216","source":{"kind":"arxiv","id":"1204.3425","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.3425","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"arxiv_version","alias_value":"1204.3425v2","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.3425","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"pith_short_12","alias_value":"7ADKRS4VYWZG","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_16","alias_value":"7ADKRS4VYWZGQCPA","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_8","alias_value":"7ADKRS4V","created_at":"2026-05-18T12:26:56Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:7ADKRS4VYWZGQCPAEH4IRISQGR","target":"record","payload":{"canonical_record":{"source":{"id":"1204.3425","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-04-16T09:48:16Z","cross_cats_sorted":["cond-mat.str-el"],"title_canon_sha256":"adb793b6c1791565256bcc01f2c33f96a730fae3eb44aaa7b0cbab9e043ca263","abstract_canon_sha256":"b4d107aed293f9e0c8293e96ff78133b4d7b3bcadc9b3821fae64ff58cbc69ca"},"schema_version":"1.0"},"canonical_sha256":"f806a8cb95c5b26809e021f888a250347b3d0c940c55afaf9e89d59657fdf216","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:53:17.135181Z","signature_b64":"8UZLZypYak3NxBqs6oXpSZzEygOB/B8vuBHZWSbwedM7BNaUM9XlhiOunjkjNUnGBWcu1mx7xx8+HL3yx14CCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f806a8cb95c5b26809e021f888a250347b3d0c940c55afaf9e89d59657fdf216","last_reissued_at":"2026-05-18T03:53:17.134462Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:53:17.134462Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1204.3425","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":"2026-05-18T03:53:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sUT4huZ5LlFR7TInBLpRUui3m6YP7FORGjpiWplJvbx8QK+aUXCo6U0Z5SekTJ0yzy5mDF4/3H7ax2CWWZ5VCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T16:39:20.156230Z"},"content_sha256":"c405c6f655a53253cc58037dcdec085ecc875a93e9b587fdc6028bdeb81261a4","schema_version":"1.0","event_id":"sha256:c405c6f655a53253cc58037dcdec085ecc875a93e9b587fdc6028bdeb81261a4"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:7ADKRS4VYWZGQCPAEH4IRISQGR","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Exact diagonalization of the Hubbard model on graphics processing units","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.str-el"],"primary_cat":"physics.comp-ph","authors_text":"Ari Harju, Topi Siro","submitted_at":"2012-04-16T09:48:16Z","abstract_excerpt":"We solve the Hubbard model with the exact diagonalization method on a graphics processing unit (GPU). We benchmark our GPU program against a sequential CPU code by using the Lanczos algorithm to solve the ground state energy in two cases: a one-dimensional ring and a two-dimensional square lattice. In the one-dimensional case, we obtain speedups of over 100 and 60 in single and double precision arithmetic, respectively. In the two-dimensional case, the corresponding speedups are over 110 and 70."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.3425","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":"2026-05-18T03:53:17Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CXO0jPbfhQdORWZSTb4JLFTdEFpNc6h5hLiuk2laoRtENmDnthENn/3hFd5Xxkojipj6WKqJtr7JvwFbi4mmAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T16:39:20.156900Z"},"content_sha256":"aeb61e9a017f68ebd4e6566c563a435a1c3c03e9708837eaf2e416cab7f5cf43","schema_version":"1.0","event_id":"sha256:aeb61e9a017f68ebd4e6566c563a435a1c3c03e9708837eaf2e416cab7f5cf43"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/bundle.json","state_url":"https://pith.science/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/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":"2026-05-27T16:39:20Z","links":{"resolver":"https://pith.science/pith/7ADKRS4VYWZGQCPAEH4IRISQGR","bundle":"https://pith.science/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/bundle.json","state":"https://pith.science/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7ADKRS4VYWZGQCPAEH4IRISQGR/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:7ADKRS4VYWZGQCPAEH4IRISQGR","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":"b4d107aed293f9e0c8293e96ff78133b4d7b3bcadc9b3821fae64ff58cbc69ca","cross_cats_sorted":["cond-mat.str-el"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-04-16T09:48:16Z","title_canon_sha256":"adb793b6c1791565256bcc01f2c33f96a730fae3eb44aaa7b0cbab9e043ca263"},"schema_version":"1.0","source":{"id":"1204.3425","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.3425","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"arxiv_version","alias_value":"1204.3425v2","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.3425","created_at":"2026-05-18T03:53:17Z"},{"alias_kind":"pith_short_12","alias_value":"7ADKRS4VYWZG","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_16","alias_value":"7ADKRS4VYWZGQCPA","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_8","alias_value":"7ADKRS4V","created_at":"2026-05-18T12:26:56Z"}],"graph_snapshots":[{"event_id":"sha256:aeb61e9a017f68ebd4e6566c563a435a1c3c03e9708837eaf2e416cab7f5cf43","target":"graph","created_at":"2026-05-18T03:53:17Z","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 solve the Hubbard model with the exact diagonalization method on a graphics processing unit (GPU). We benchmark our GPU program against a sequential CPU code by using the Lanczos algorithm to solve the ground state energy in two cases: a one-dimensional ring and a two-dimensional square lattice. In the one-dimensional case, we obtain speedups of over 100 and 60 in single and double precision arithmetic, respectively. In the two-dimensional case, the corresponding speedups are over 110 and 70.","authors_text":"Ari Harju, Topi Siro","cross_cats":["cond-mat.str-el"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-04-16T09:48:16Z","title":"Exact diagonalization of the Hubbard model on graphics processing units"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.3425","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:c405c6f655a53253cc58037dcdec085ecc875a93e9b587fdc6028bdeb81261a4","target":"record","created_at":"2026-05-18T03:53:17Z","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":"b4d107aed293f9e0c8293e96ff78133b4d7b3bcadc9b3821fae64ff58cbc69ca","cross_cats_sorted":["cond-mat.str-el"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.comp-ph","submitted_at":"2012-04-16T09:48:16Z","title_canon_sha256":"adb793b6c1791565256bcc01f2c33f96a730fae3eb44aaa7b0cbab9e043ca263"},"schema_version":"1.0","source":{"id":"1204.3425","kind":"arxiv","version":2}},"canonical_sha256":"f806a8cb95c5b26809e021f888a250347b3d0c940c55afaf9e89d59657fdf216","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f806a8cb95c5b26809e021f888a250347b3d0c940c55afaf9e89d59657fdf216","first_computed_at":"2026-05-18T03:53:17.134462Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:53:17.134462Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"8UZLZypYak3NxBqs6oXpSZzEygOB/B8vuBHZWSbwedM7BNaUM9XlhiOunjkjNUnGBWcu1mx7xx8+HL3yx14CCw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:53:17.135181Z","signed_message":"canonical_sha256_bytes"},"source_id":"1204.3425","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c405c6f655a53253cc58037dcdec085ecc875a93e9b587fdc6028bdeb81261a4","sha256:aeb61e9a017f68ebd4e6566c563a435a1c3c03e9708837eaf2e416cab7f5cf43"],"state_sha256":"515081c11cd10687e1594cff298a53fe6e6b99f98c72a36357ac5905e9f7aa68"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"IePzLZixWjgbQKFG3HXtiss4Phy8phJTmrrXEiG9fBlUITnXg1zX+KmDw8hki87jJADeM3FuEc+8F7Q4+EcgDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T16:39:20.160636Z","bundle_sha256":"c2e9a4999391e871339243ad24725b3f1ed5c68a7798598c86bebdf6b2425d5c"}}