{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:7DETRYS7B5R7NUIJDUXTUF5OT6","short_pith_number":"pith:7DETRYS7","canonical_record":{"source":{"id":"1210.6613","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-10-24T17:37:17Z","cross_cats_sorted":["cond-mat.str-el"],"title_canon_sha256":"afde11a99393cc78034d58c9d43a06d4e07df51d9b07909f6c3ce676b2d62e70","abstract_canon_sha256":"df53be605a466a311b01e503db13414ea9822a072c1fb047be2345ba7b69bd51"},"schema_version":"1.0"},"canonical_sha256":"f8c938e25f0f63f6d1091d2f3a17ae9fa2ccaa3a3665d3f5e51da5d7f6a37c4e","source":{"kind":"arxiv","id":"1210.6613","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1210.6613","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"arxiv_version","alias_value":"1210.6613v2","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1210.6613","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"pith_short_12","alias_value":"7DETRYS7B5R7","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_16","alias_value":"7DETRYS7B5R7NUIJ","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_8","alias_value":"7DETRYS7","created_at":"2026-05-18T12:26:56Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:7DETRYS7B5R7NUIJDUXTUF5OT6","target":"record","payload":{"canonical_record":{"source":{"id":"1210.6613","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-10-24T17:37:17Z","cross_cats_sorted":["cond-mat.str-el"],"title_canon_sha256":"afde11a99393cc78034d58c9d43a06d4e07df51d9b07909f6c3ce676b2d62e70","abstract_canon_sha256":"df53be605a466a311b01e503db13414ea9822a072c1fb047be2345ba7b69bd51"},"schema_version":"1.0"},"canonical_sha256":"f8c938e25f0f63f6d1091d2f3a17ae9fa2ccaa3a3665d3f5e51da5d7f6a37c4e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:30:08.746800Z","signature_b64":"3wFxinHy3L7gDu2rIjB4W1Ft9mBTn7pY/GAr99DjqI0GRyipqbO+hNbT3IYESvYo/fEionkG+6u1nmxqV00wAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f8c938e25f0f63f6d1091d2f3a17ae9fa2ccaa3a3665d3f5e51da5d7f6a37c4e","last_reissued_at":"2026-05-18T02:30:08.746286Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:30:08.746286Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1210.6613","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":"2026-05-18T02:30:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ieqTF5Od4/7K4HOr6OA4b1Xzy+kEccXvu1aa0Y5nNhSlZMzOvA9l4ZmZ313kJaIJXt4p3ol9cMeV9kv4uXIuDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T20:33:53.419670Z"},"content_sha256":"0fee497d1b63c2774eeae4358b32c090b138ecd22c9b37717088409ff4e301a5","schema_version":"1.0","event_id":"sha256:0fee497d1b63c2774eeae4358b32c090b138ecd22c9b37717088409ff4e301a5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:7DETRYS7B5R7NUIJDUXTUF5OT6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Frustration free gapless Hamiltonians for Matrix Product States","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.str-el"],"primary_cat":"quant-ph","authors_text":"Carlos Fern\\'andez-Gonz\\'alez, David P\\'erez-Garc\\'ia, J. Ignacio Cirac, Michael M. Wolf, Norbert Schuch","submitted_at":"2012-10-24T17:37:17Z","abstract_excerpt":"For every Matrix Product State (MPS) one can always construct a so-called parent Hamiltonian. This is a local, frustration free, Hamiltonian which has the MPS as ground state and is gapped. Whenever that parent Hamiltonian has a degenerate ground state (the so-called non-injective case), we construct another 'uncle' Hamiltonian which is local and frustration free but gapless, and its spectrum is $\\R^+$. The construction is obtained by linearly perturbing the matrices building up the state in a random direction, and then taking the limit where the perturbation goes to zero. For MPS where the pa"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.6613","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":"2026-05-18T02:30:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dTIgsC5ULa06mqKZSKpbLXdl834EKsG0na+e1PX4adqsbvDgIJo+PVJhdjkbYLqO8W72rcHi2HQ4qUEYr3/sBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-22T20:33:53.420016Z"},"content_sha256":"32a16cd36f12022fee414a97758177dd048d8efb3d242aa58248d31dbcfd3198","schema_version":"1.0","event_id":"sha256:32a16cd36f12022fee414a97758177dd048d8efb3d242aa58248d31dbcfd3198"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/bundle.json","state_url":"https://pith.science/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/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":"2026-05-22T20:33:53Z","links":{"resolver":"https://pith.science/pith/7DETRYS7B5R7NUIJDUXTUF5OT6","bundle":"https://pith.science/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/bundle.json","state":"https://pith.science/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7DETRYS7B5R7NUIJDUXTUF5OT6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:7DETRYS7B5R7NUIJDUXTUF5OT6","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":"df53be605a466a311b01e503db13414ea9822a072c1fb047be2345ba7b69bd51","cross_cats_sorted":["cond-mat.str-el"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-10-24T17:37:17Z","title_canon_sha256":"afde11a99393cc78034d58c9d43a06d4e07df51d9b07909f6c3ce676b2d62e70"},"schema_version":"1.0","source":{"id":"1210.6613","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1210.6613","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"arxiv_version","alias_value":"1210.6613v2","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1210.6613","created_at":"2026-05-18T02:30:08Z"},{"alias_kind":"pith_short_12","alias_value":"7DETRYS7B5R7","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_16","alias_value":"7DETRYS7B5R7NUIJ","created_at":"2026-05-18T12:26:56Z"},{"alias_kind":"pith_short_8","alias_value":"7DETRYS7","created_at":"2026-05-18T12:26:56Z"}],"graph_snapshots":[{"event_id":"sha256:32a16cd36f12022fee414a97758177dd048d8efb3d242aa58248d31dbcfd3198","target":"graph","created_at":"2026-05-18T02:30:08Z","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":"For every Matrix Product State (MPS) one can always construct a so-called parent Hamiltonian. This is a local, frustration free, Hamiltonian which has the MPS as ground state and is gapped. Whenever that parent Hamiltonian has a degenerate ground state (the so-called non-injective case), we construct another 'uncle' Hamiltonian which is local and frustration free but gapless, and its spectrum is $\\R^+$. The construction is obtained by linearly perturbing the matrices building up the state in a random direction, and then taking the limit where the perturbation goes to zero. For MPS where the pa","authors_text":"Carlos Fern\\'andez-Gonz\\'alez, David P\\'erez-Garc\\'ia, J. Ignacio Cirac, Michael M. Wolf, Norbert Schuch","cross_cats":["cond-mat.str-el"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-10-24T17:37:17Z","title":"Frustration free gapless Hamiltonians for Matrix Product States"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.6613","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":"sha256:0fee497d1b63c2774eeae4358b32c090b138ecd22c9b37717088409ff4e301a5","target":"record","created_at":"2026-05-18T02:30:08Z","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":"df53be605a466a311b01e503db13414ea9822a072c1fb047be2345ba7b69bd51","cross_cats_sorted":["cond-mat.str-el"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-10-24T17:37:17Z","title_canon_sha256":"afde11a99393cc78034d58c9d43a06d4e07df51d9b07909f6c3ce676b2d62e70"},"schema_version":"1.0","source":{"id":"1210.6613","kind":"arxiv","version":2}},"canonical_sha256":"f8c938e25f0f63f6d1091d2f3a17ae9fa2ccaa3a3665d3f5e51da5d7f6a37c4e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f8c938e25f0f63f6d1091d2f3a17ae9fa2ccaa3a3665d3f5e51da5d7f6a37c4e","first_computed_at":"2026-05-18T02:30:08.746286Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:30:08.746286Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"3wFxinHy3L7gDu2rIjB4W1Ft9mBTn7pY/GAr99DjqI0GRyipqbO+hNbT3IYESvYo/fEionkG+6u1nmxqV00wAA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:30:08.746800Z","signed_message":"canonical_sha256_bytes"},"source_id":"1210.6613","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0fee497d1b63c2774eeae4358b32c090b138ecd22c9b37717088409ff4e301a5","sha256:32a16cd36f12022fee414a97758177dd048d8efb3d242aa58248d31dbcfd3198"],"state_sha256":"971531caab234e791266df7e02720fc4dd452bca15d1b364b2b12681dc9d23ab"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"cEPUMvkib0mzYjYlDFwOzZ+OD5DQ1iBdCt7TuakWi6kYmxSIjjLadvL/zNMzfQV4FFH6hSRS5rYxriTxa8hACA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-22T20:33:53.422453Z","bundle_sha256":"e7639cb03a7bee5cd6ff3ac0e7e30a8aad6b4f3fe44658979191f7a8b073cd32"}}