{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:YK7WW75ZX7FGJTQAUHUM4FPTFU","short_pith_number":"pith:YK7WW75Z","canonical_record":{"source":{"id":"2104.04394","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"gr-qc","submitted_at":"2021-04-09T14:32:40Z","cross_cats_sorted":["hep-th"],"title_canon_sha256":"eae198bb3370075ea8abf104540369224239289c6f29231ec169da69f2e360af","abstract_canon_sha256":"645b2835e7cc3f4ff68092cf63c52cb68230b1932fde6e3e3b156c1b8f6386e9"},"schema_version":"1.0"},"canonical_sha256":"c2bf6b7fb9bfca64ce00a1e8ce15f32d078a8d6bab4c59bf18931ac510cfca6b","source":{"kind":"arxiv","id":"2104.04394","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.04394","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"arxiv_version","alias_value":"2104.04394v1","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.04394","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_12","alias_value":"YK7WW75ZX7FG","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_16","alias_value":"YK7WW75ZX7FGJTQA","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_8","alias_value":"YK7WW75Z","created_at":"2026-07-05T02:30:38Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:YK7WW75ZX7FGJTQAUHUM4FPTFU","target":"record","payload":{"canonical_record":{"source":{"id":"2104.04394","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"gr-qc","submitted_at":"2021-04-09T14:32:40Z","cross_cats_sorted":["hep-th"],"title_canon_sha256":"eae198bb3370075ea8abf104540369224239289c6f29231ec169da69f2e360af","abstract_canon_sha256":"645b2835e7cc3f4ff68092cf63c52cb68230b1932fde6e3e3b156c1b8f6386e9"},"schema_version":"1.0"},"canonical_sha256":"c2bf6b7fb9bfca64ce00a1e8ce15f32d078a8d6bab4c59bf18931ac510cfca6b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:30:38.842302Z","signature_b64":"w5vqYKasrQ08110MZQwJ8eK/N5BmbY8I0dcmUYIcxqmaJGjGeUc7EnpArwYUAT9tRN1CGrebJbhnWx8SNvKMCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c2bf6b7fb9bfca64ce00a1e8ce15f32d078a8d6bab4c59bf18931ac510cfca6b","last_reissued_at":"2026-07-05T02:30:38.841830Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:30:38.841830Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2104.04394","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":"2026-07-05T02:30:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pG62/PSXqTQK8CjYDTrxTV2oAN0oKeVNVkSlgTf1bchwWahcci3il+mX9I4cFmw81g0Ahx5H2tISnnUWDcESCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T02:50:16.965048Z"},"content_sha256":"7bcc710f5d203c2ea9e7b381f714fd22e7a02381f56fbc73e7440867b519a4e7","schema_version":"1.0","event_id":"sha256:7bcc710f5d203c2ea9e7b381f714fd22e7a02381f56fbc73e7440867b519a4e7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:YK7WW75ZX7FGJTQAUHUM4FPTFU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Short Review of Loop Quantum Gravity","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":["hep-th"],"primary_cat":"gr-qc","authors_text":"Abhay Ashtekar, Eugenio Bianchi","submitted_at":"2021-04-09T14:32:40Z","abstract_excerpt":"An outstanding open issue in our quest for physics beyond Einstein is the unification of general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading approach toward this goal. At its heart is the central lesson of GR: Gravity is a manifestation of spacetime geometry. Thus, the approach emphasizes the quantum nature of geometry and focuses on its implications in extreme regimes -- near the big bang and inside black holes -- where Einstein's smooth continuum breaks down. We present a brief overview of the main ideas underlying LQG and highlight a few recent advances. Thi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.04394","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/2104.04394/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":"2026-07-05T02:30:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"51znrVy8xdfreiLJPOEqhl+Dd7ohnao00tKfjO10FQnnuH+TwOyhbIzi0//yoQ3pmdmsxAQ+fu/G5OD9sTJkBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T02:50:16.965551Z"},"content_sha256":"ba324dbd58a40445cb110a72dd65d7978bd94db69c433b31607f6bf608aea9fc","schema_version":"1.0","event_id":"sha256:ba324dbd58a40445cb110a72dd65d7978bd94db69c433b31607f6bf608aea9fc"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/bundle.json","state_url":"https://pith.science/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/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":"2026-08-04T02:50:16Z","links":{"resolver":"https://pith.science/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU","bundle":"https://pith.science/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/bundle.json","state":"https://pith.science/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/YK7WW75ZX7FGJTQAUHUM4FPTFU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:YK7WW75ZX7FGJTQAUHUM4FPTFU","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":"645b2835e7cc3f4ff68092cf63c52cb68230b1932fde6e3e3b156c1b8f6386e9","cross_cats_sorted":["hep-th"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"gr-qc","submitted_at":"2021-04-09T14:32:40Z","title_canon_sha256":"eae198bb3370075ea8abf104540369224239289c6f29231ec169da69f2e360af"},"schema_version":"1.0","source":{"id":"2104.04394","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.04394","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"arxiv_version","alias_value":"2104.04394v1","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.04394","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_12","alias_value":"YK7WW75ZX7FG","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_16","alias_value":"YK7WW75ZX7FGJTQA","created_at":"2026-07-05T02:30:38Z"},{"alias_kind":"pith_short_8","alias_value":"YK7WW75Z","created_at":"2026-07-05T02:30:38Z"}],"graph_snapshots":[{"event_id":"sha256:ba324dbd58a40445cb110a72dd65d7978bd94db69c433b31607f6bf608aea9fc","target":"graph","created_at":"2026-07-05T02:30:38Z","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/2104.04394/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"An outstanding open issue in our quest for physics beyond Einstein is the unification of general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading approach toward this goal. At its heart is the central lesson of GR: Gravity is a manifestation of spacetime geometry. Thus, the approach emphasizes the quantum nature of geometry and focuses on its implications in extreme regimes -- near the big bang and inside black holes -- where Einstein's smooth continuum breaks down. We present a brief overview of the main ideas underlying LQG and highlight a few recent advances. Thi","authors_text":"Abhay Ashtekar, Eugenio Bianchi","cross_cats":["hep-th"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"gr-qc","submitted_at":"2021-04-09T14:32:40Z","title":"A Short Review of Loop Quantum Gravity"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.04394","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":"sha256:7bcc710f5d203c2ea9e7b381f714fd22e7a02381f56fbc73e7440867b519a4e7","target":"record","created_at":"2026-07-05T02:30:38Z","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":"645b2835e7cc3f4ff68092cf63c52cb68230b1932fde6e3e3b156c1b8f6386e9","cross_cats_sorted":["hep-th"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"gr-qc","submitted_at":"2021-04-09T14:32:40Z","title_canon_sha256":"eae198bb3370075ea8abf104540369224239289c6f29231ec169da69f2e360af"},"schema_version":"1.0","source":{"id":"2104.04394","kind":"arxiv","version":1}},"canonical_sha256":"c2bf6b7fb9bfca64ce00a1e8ce15f32d078a8d6bab4c59bf18931ac510cfca6b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c2bf6b7fb9bfca64ce00a1e8ce15f32d078a8d6bab4c59bf18931ac510cfca6b","first_computed_at":"2026-07-05T02:30:38.841830Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:30:38.841830Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"w5vqYKasrQ08110MZQwJ8eK/N5BmbY8I0dcmUYIcxqmaJGjGeUc7EnpArwYUAT9tRN1CGrebJbhnWx8SNvKMCw==","signature_status":"signed_v1","signed_at":"2026-07-05T02:30:38.842302Z","signed_message":"canonical_sha256_bytes"},"source_id":"2104.04394","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7bcc710f5d203c2ea9e7b381f714fd22e7a02381f56fbc73e7440867b519a4e7","sha256:ba324dbd58a40445cb110a72dd65d7978bd94db69c433b31607f6bf608aea9fc"],"state_sha256":"845bdeea66fcb12345c37f151367995f844ab6531dc51c2b9190805711bb6f79"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bSdmdyiq28qo8IzPGiXfyqYjI4LdSORVsdnRB0+eBmtbtkNkui1nXBoBW+FWaJGR6A1qVMbJjYOn9N9PFzPaCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-04T02:50:16.968884Z","bundle_sha256":"da9454c363ffff48cbdabaae0ee7dcea86c82d3bd7ee7062875d0501901cf387"}}