{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:MDEE2OVFSEK7IQXRQY53O4DIU7","short_pith_number":"pith:MDEE2OVF","canonical_record":{"source":{"id":"1311.3279","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2013-11-13T20:19:36Z","cross_cats_sorted":[],"title_canon_sha256":"df30ccb4ff06cd189a7161f6027d28596f6c0c91b33784b26968ead09d9955d1","abstract_canon_sha256":"020bb281102742713920cc604b83c8a1c6e17cd9a8621f7d761f1e30a95764a7"},"schema_version":"1.0"},"canonical_sha256":"60c84d3aa59115f442f1863bb77068a7ca5dd145773e0d001291007fb7e896f2","source":{"kind":"arxiv","id":"1311.3279","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.3279","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"arxiv_version","alias_value":"1311.3279v2","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.3279","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"pith_short_12","alias_value":"MDEE2OVFSEK7","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_16","alias_value":"MDEE2OVFSEK7IQXR","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_8","alias_value":"MDEE2OVF","created_at":"2026-05-18T12:27:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:MDEE2OVFSEK7IQXRQY53O4DIU7","target":"record","payload":{"canonical_record":{"source":{"id":"1311.3279","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2013-11-13T20:19:36Z","cross_cats_sorted":[],"title_canon_sha256":"df30ccb4ff06cd189a7161f6027d28596f6c0c91b33784b26968ead09d9955d1","abstract_canon_sha256":"020bb281102742713920cc604b83c8a1c6e17cd9a8621f7d761f1e30a95764a7"},"schema_version":"1.0"},"canonical_sha256":"60c84d3aa59115f442f1863bb77068a7ca5dd145773e0d001291007fb7e896f2","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:52:58.196997Z","signature_b64":"nSuk0C8L+63bQuyr/SZ0VMtaRSN136JsjMrU5jMkr/onrRZ9KtQ9+q2tndvHMLuFmO0KEnG91fN1/2XO54IIBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"60c84d3aa59115f442f1863bb77068a7ca5dd145773e0d001291007fb7e896f2","last_reissued_at":"2026-05-18T02:52:58.196479Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:52:58.196479Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1311.3279","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":"2026-05-18T02:52:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HTe3cczkIY8+z2kwYw4R3OMyZ7ZISTaHv+Fed6q/38nL6OAPAIIFKMZsQaAxskFLJKRx9i/+IJVIOUPm9eWOCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T21:55:54.581235Z"},"content_sha256":"1a31b9383cca6b4de99e62a46269c3d319d810b9244dd7dc1e5e961146195cf3","schema_version":"1.0","event_id":"sha256:1a31b9383cca6b4de99e62a46269c3d319d810b9244dd7dc1e5e961146195cf3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:MDEE2OVFSEK7IQXRQY53O4DIU7","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Null twisted geometries","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"Mingyi Zhang, Simone Speziale","submitted_at":"2013-11-13T20:19:36Z","abstract_excerpt":"We define and investigate a quantisation of null hypersurfaces in the context of loop quantum gravity on a fixed graph. The main tool we use is the parametrisation of the theory in terms of twistors, which has already proved useful in discussing the interpretation of spin networks as the quantization of twisted geometries. The classical formalism can be extended in a natural way to null hypersurfaces, with the Euclidean polyhedra replaced by null polyhedra with space-like faces, and SU(2) by the little group ISO(2). The main difference is that the simplicity constraints present in the formalim"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.3279","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":"2026-05-18T02:52:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ZtwSokehoSjy92Mh7BYpjoII8AFYNUykfsAhG0QBuFhm40FwPL5ZUMwVg8DrcSGL8cynLki0eDuyZF8KvkuhDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T21:55:54.581599Z"},"content_sha256":"8dec56e0baeaa17ea20c0cd2c3d4275b22fe80772b75cd28ebf73c67b10c9e1f","schema_version":"1.0","event_id":"sha256:8dec56e0baeaa17ea20c0cd2c3d4275b22fe80772b75cd28ebf73c67b10c9e1f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/bundle.json","state_url":"https://pith.science/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/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":"2026-06-02T21:55:54Z","links":{"resolver":"https://pith.science/pith/MDEE2OVFSEK7IQXRQY53O4DIU7","bundle":"https://pith.science/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/bundle.json","state":"https://pith.science/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MDEE2OVFSEK7IQXRQY53O4DIU7/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:MDEE2OVFSEK7IQXRQY53O4DIU7","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":"020bb281102742713920cc604b83c8a1c6e17cd9a8621f7d761f1e30a95764a7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2013-11-13T20:19:36Z","title_canon_sha256":"df30ccb4ff06cd189a7161f6027d28596f6c0c91b33784b26968ead09d9955d1"},"schema_version":"1.0","source":{"id":"1311.3279","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.3279","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"arxiv_version","alias_value":"1311.3279v2","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.3279","created_at":"2026-05-18T02:52:58Z"},{"alias_kind":"pith_short_12","alias_value":"MDEE2OVFSEK7","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_16","alias_value":"MDEE2OVFSEK7IQXR","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_8","alias_value":"MDEE2OVF","created_at":"2026-05-18T12:27:52Z"}],"graph_snapshots":[{"event_id":"sha256:8dec56e0baeaa17ea20c0cd2c3d4275b22fe80772b75cd28ebf73c67b10c9e1f","target":"graph","created_at":"2026-05-18T02:52:58Z","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 define and investigate a quantisation of null hypersurfaces in the context of loop quantum gravity on a fixed graph. The main tool we use is the parametrisation of the theory in terms of twistors, which has already proved useful in discussing the interpretation of spin networks as the quantization of twisted geometries. The classical formalism can be extended in a natural way to null hypersurfaces, with the Euclidean polyhedra replaced by null polyhedra with space-like faces, and SU(2) by the little group ISO(2). The main difference is that the simplicity constraints present in the formalim","authors_text":"Mingyi Zhang, Simone Speziale","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2013-11-13T20:19:36Z","title":"Null twisted geometries"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.3279","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":"sha256:1a31b9383cca6b4de99e62a46269c3d319d810b9244dd7dc1e5e961146195cf3","target":"record","created_at":"2026-05-18T02:52:58Z","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":"020bb281102742713920cc604b83c8a1c6e17cd9a8621f7d761f1e30a95764a7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2013-11-13T20:19:36Z","title_canon_sha256":"df30ccb4ff06cd189a7161f6027d28596f6c0c91b33784b26968ead09d9955d1"},"schema_version":"1.0","source":{"id":"1311.3279","kind":"arxiv","version":2}},"canonical_sha256":"60c84d3aa59115f442f1863bb77068a7ca5dd145773e0d001291007fb7e896f2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"60c84d3aa59115f442f1863bb77068a7ca5dd145773e0d001291007fb7e896f2","first_computed_at":"2026-05-18T02:52:58.196479Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:52:58.196479Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"nSuk0C8L+63bQuyr/SZ0VMtaRSN136JsjMrU5jMkr/onrRZ9KtQ9+q2tndvHMLuFmO0KEnG91fN1/2XO54IIBw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:52:58.196997Z","signed_message":"canonical_sha256_bytes"},"source_id":"1311.3279","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1a31b9383cca6b4de99e62a46269c3d319d810b9244dd7dc1e5e961146195cf3","sha256:8dec56e0baeaa17ea20c0cd2c3d4275b22fe80772b75cd28ebf73c67b10c9e1f"],"state_sha256":"2035a62cb84d22023809886e111d08aeeebf5f200a5220fa8cc7adeb98a6747d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"N/wNOpvDy/GuvcfrqDAGDZBAzAEJoshn47BabV8G9S4xTg2ACkylQ+8hGmilt1SjZx1EXOm2DiOqtzpDs+ilBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-02T21:55:54.585375Z","bundle_sha256":"f91f3473551c37e6a790fb312e6c5e02f77c40459e1b6e4cee3a6b4ead49e8b6"}}