{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:ORUCDV7XYXT2NR5H4CSKOK3LMB","short_pith_number":"pith:ORUCDV7X","canonical_record":{"source":{"id":"1201.2187","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-01-10T21:19:44Z","cross_cats_sorted":[],"title_canon_sha256":"4bb1315b60fc96860ff3da34225510fee2afcb358a7cac9b610848d005784c4c","abstract_canon_sha256":"602749e26c05b1a001fd5d7159235da946abc02914ed592dde1b400a604ba3fb"},"schema_version":"1.0"},"canonical_sha256":"746821d7f7c5e7a6c7a7e0a4a72b6b605350d9be558bc81774c63bf86a6331eb","source":{"kind":"arxiv","id":"1201.2187","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1201.2187","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"arxiv_version","alias_value":"1201.2187v2","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1201.2187","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"pith_short_12","alias_value":"ORUCDV7XYXT2","created_at":"2026-05-18T12:27:16Z"},{"alias_kind":"pith_short_16","alias_value":"ORUCDV7XYXT2NR5H","created_at":"2026-05-18T12:27:16Z"},{"alias_kind":"pith_short_8","alias_value":"ORUCDV7X","created_at":"2026-05-18T12:27:16Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:ORUCDV7XYXT2NR5H4CSKOK3LMB","target":"record","payload":{"canonical_record":{"source":{"id":"1201.2187","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-01-10T21:19:44Z","cross_cats_sorted":[],"title_canon_sha256":"4bb1315b60fc96860ff3da34225510fee2afcb358a7cac9b610848d005784c4c","abstract_canon_sha256":"602749e26c05b1a001fd5d7159235da946abc02914ed592dde1b400a604ba3fb"},"schema_version":"1.0"},"canonical_sha256":"746821d7f7c5e7a6c7a7e0a4a72b6b605350d9be558bc81774c63bf86a6331eb","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:58:53.064626Z","signature_b64":"KqM0oAqTrjsRyk2xuLH4bBOYq4DZCCwKBjSxRIPnRJdos2t8CvWEVjCtRcXsmmpCV0HckoH6fe2byo1qMufUDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"746821d7f7c5e7a6c7a7e0a4a72b6b605350d9be558bc81774c63bf86a6331eb","last_reissued_at":"2026-05-18T01:58:53.063958Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:58:53.063958Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1201.2187","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":"2026-05-18T01:58:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yRUh0643hxi48Mmr7InjCukeKlBYc1jgiHj1SUmiTltVJvHvQp58YTiRbIheymiiz2t0J9wIQcGuyycLm5BUDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T22:00:02.783576Z"},"content_sha256":"cdbcb877574b21d4ac8fd58126497b70c8ddbc00a9f963b4ea4868eb9db53a1f","schema_version":"1.0","event_id":"sha256:cdbcb877574b21d4ac8fd58126497b70c8ddbc00a9f963b4ea4868eb9db53a1f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:ORUCDV7XYXT2NR5H4CSKOK3LMB","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A spin-foam vertex amplitude with the correct semiclassical limit","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"Jonathan Engle","submitted_at":"2012-01-10T21:19:44Z","abstract_excerpt":"Spin-foam models are hoped to provide a dynamics for loop quantum gravity. These start from the Plebanski formulation of gravity, in which gravity is obtained from a topological field theory, BF theory, through constraints, which, however, select more than one gravitational sector, as well as an unphysical degenerate sector. We show this is why terms beyond the needed Feynman-prescribed one appear in the semiclassical limit of the EPRL spin-foam amplitude. By quantum mechanically isolating a single gravitational sector, we modify this amplitude, yielding a spin-foam amplitude for loop quantum "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1201.2187","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":"2026-05-18T01:58:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"SyuOo/PTl7ZqA/VtBPbc03Qh882p+y4L5DjUzFfkNVdCxcIGfVsrRa1TlSGjUJyzn7EBbxH88FYx0n7IYsRNCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T22:00:02.784122Z"},"content_sha256":"18bbe39638fcfab28ebc453ece3480a0ade107377f50892b696c4798f0ef6170","schema_version":"1.0","event_id":"sha256:18bbe39638fcfab28ebc453ece3480a0ade107377f50892b696c4798f0ef6170"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/bundle.json","state_url":"https://pith.science/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/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":"2026-05-21T22:00:02Z","links":{"resolver":"https://pith.science/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB","bundle":"https://pith.science/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/bundle.json","state":"https://pith.science/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ORUCDV7XYXT2NR5H4CSKOK3LMB/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:ORUCDV7XYXT2NR5H4CSKOK3LMB","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":"602749e26c05b1a001fd5d7159235da946abc02914ed592dde1b400a604ba3fb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-01-10T21:19:44Z","title_canon_sha256":"4bb1315b60fc96860ff3da34225510fee2afcb358a7cac9b610848d005784c4c"},"schema_version":"1.0","source":{"id":"1201.2187","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1201.2187","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"arxiv_version","alias_value":"1201.2187v2","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1201.2187","created_at":"2026-05-18T01:58:53Z"},{"alias_kind":"pith_short_12","alias_value":"ORUCDV7XYXT2","created_at":"2026-05-18T12:27:16Z"},{"alias_kind":"pith_short_16","alias_value":"ORUCDV7XYXT2NR5H","created_at":"2026-05-18T12:27:16Z"},{"alias_kind":"pith_short_8","alias_value":"ORUCDV7X","created_at":"2026-05-18T12:27:16Z"}],"graph_snapshots":[{"event_id":"sha256:18bbe39638fcfab28ebc453ece3480a0ade107377f50892b696c4798f0ef6170","target":"graph","created_at":"2026-05-18T01:58:53Z","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":"Spin-foam models are hoped to provide a dynamics for loop quantum gravity. These start from the Plebanski formulation of gravity, in which gravity is obtained from a topological field theory, BF theory, through constraints, which, however, select more than one gravitational sector, as well as an unphysical degenerate sector. We show this is why terms beyond the needed Feynman-prescribed one appear in the semiclassical limit of the EPRL spin-foam amplitude. By quantum mechanically isolating a single gravitational sector, we modify this amplitude, yielding a spin-foam amplitude for loop quantum ","authors_text":"Jonathan Engle","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-01-10T21:19:44Z","title":"A spin-foam vertex amplitude with the correct semiclassical limit"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1201.2187","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:cdbcb877574b21d4ac8fd58126497b70c8ddbc00a9f963b4ea4868eb9db53a1f","target":"record","created_at":"2026-05-18T01:58:53Z","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":"602749e26c05b1a001fd5d7159235da946abc02914ed592dde1b400a604ba3fb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2012-01-10T21:19:44Z","title_canon_sha256":"4bb1315b60fc96860ff3da34225510fee2afcb358a7cac9b610848d005784c4c"},"schema_version":"1.0","source":{"id":"1201.2187","kind":"arxiv","version":2}},"canonical_sha256":"746821d7f7c5e7a6c7a7e0a4a72b6b605350d9be558bc81774c63bf86a6331eb","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"746821d7f7c5e7a6c7a7e0a4a72b6b605350d9be558bc81774c63bf86a6331eb","first_computed_at":"2026-05-18T01:58:53.063958Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:58:53.063958Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"KqM0oAqTrjsRyk2xuLH4bBOYq4DZCCwKBjSxRIPnRJdos2t8CvWEVjCtRcXsmmpCV0HckoH6fe2byo1qMufUDA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:58:53.064626Z","signed_message":"canonical_sha256_bytes"},"source_id":"1201.2187","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:cdbcb877574b21d4ac8fd58126497b70c8ddbc00a9f963b4ea4868eb9db53a1f","sha256:18bbe39638fcfab28ebc453ece3480a0ade107377f50892b696c4798f0ef6170"],"state_sha256":"3484ab7dba5a4e4e90abe958064db60864656c20123f5e1c81101e23db8ce584"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"e7gNLyO0emo1ot+XQYfdnMMvysJsno+S8SxgYIQCv1SLQy3Guzi7RkNEzw58BQKawX82LHXOeFNJaKZsFrmLAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-21T22:00:02.787502Z","bundle_sha256":"96a9b52e9e73966a1df4a05afa7437ad281a4d5e5fe983bbd889895ba4942da9"}}