{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:QUNFCQJXIMTGUMUMGCD6V4R366","short_pith_number":"pith:QUNFCQJX","canonical_record":{"source":{"id":"1603.04732","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-03-15T15:59:33Z","cross_cats_sorted":["math-ph","math.MP"],"title_canon_sha256":"a1f76c5c0f030813e858977dd5815b90ce651cd4196a695d1117fa834512339e","abstract_canon_sha256":"74811c1b72b5b7c6b5fa72101225385262bb2341132a7daff64a276b6348d40d"},"schema_version":"1.0"},"canonical_sha256":"851a51413743266a328c3087eaf23bf7b44291261b73942ad21f36d23a4ca3c9","source":{"kind":"arxiv","id":"1603.04732","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1603.04732","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"arxiv_version","alias_value":"1603.04732v2","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1603.04732","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"pith_short_12","alias_value":"QUNFCQJXIMTG","created_at":"2026-05-18T12:30:41Z"},{"alias_kind":"pith_short_16","alias_value":"QUNFCQJXIMTGUMUM","created_at":"2026-05-18T12:30:41Z"},{"alias_kind":"pith_short_8","alias_value":"QUNFCQJX","created_at":"2026-05-18T12:30:41Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:QUNFCQJXIMTGUMUMGCD6V4R366","target":"record","payload":{"canonical_record":{"source":{"id":"1603.04732","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-03-15T15:59:33Z","cross_cats_sorted":["math-ph","math.MP"],"title_canon_sha256":"a1f76c5c0f030813e858977dd5815b90ce651cd4196a695d1117fa834512339e","abstract_canon_sha256":"74811c1b72b5b7c6b5fa72101225385262bb2341132a7daff64a276b6348d40d"},"schema_version":"1.0"},"canonical_sha256":"851a51413743266a328c3087eaf23bf7b44291261b73942ad21f36d23a4ca3c9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:11:48.362726Z","signature_b64":"1UB9kgjW0KYwn4g6Y3fIfi2AN2eII2+TE+V/DSgjR8Mr6qDaRKQd69jqVR0HvMSPU/HakTFwKHRG7lUlrd3ZBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"851a51413743266a328c3087eaf23bf7b44291261b73942ad21f36d23a4ca3c9","last_reissued_at":"2026-05-18T01:11:48.362277Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:11:48.362277Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1603.04732","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":"2026-05-18T01:11:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"jNRZboUngOPw3e5lHYn3uKoB63n14mzUCay3WT3R5LwLjU362qWE4IO9imamnNq5Hj+yhnHf4t5H/uImOEI0CA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:54:55.853084Z"},"content_sha256":"2dcb18a171f85548105ff998de7f8c4617e6ac596f2288c956a4a5b7715c8d88","schema_version":"1.0","event_id":"sha256:2dcb18a171f85548105ff998de7f8c4617e6ac596f2288c956a4a5b7715c8d88"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:QUNFCQJXIMTGUMUMGCD6V4R366","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Principal Symbol of Euler-Lagrange Operators","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math-ph","math.MP"],"primary_cat":"gr-qc","authors_text":"Lorenzo Fatibene, Simon Garruto","submitted_at":"2016-03-15T15:59:33Z","abstract_excerpt":"We shall introduce the principal symbol for Euler-Lagrange operators and use them to charac- terise well-posed initial value problems. We shall clarify how constraints can arise in Lagrangian covariant theories by extending the standard treatment in GR. Finally, we sketch a quantization procedure based on what done in LQG."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1603.04732","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":"2026-05-18T01:11:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dINsfRoHBMYII1WNfDOR2hmtv6PfI/HkpxpcuiEMNBXGNzgpYxItklfHGKeCY8h8RgXVypYzkpwgwcxRXrFZCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T06:54:55.853452Z"},"content_sha256":"e3c88e56e966556112e1ce22bb2beaf03e2ca7a2181f7cadf577502355916fe9","schema_version":"1.0","event_id":"sha256:e3c88e56e966556112e1ce22bb2beaf03e2ca7a2181f7cadf577502355916fe9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QUNFCQJXIMTGUMUMGCD6V4R366/bundle.json","state_url":"https://pith.science/pith/QUNFCQJXIMTGUMUMGCD6V4R366/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QUNFCQJXIMTGUMUMGCD6V4R366/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":"2026-05-30T06:54:55Z","links":{"resolver":"https://pith.science/pith/QUNFCQJXIMTGUMUMGCD6V4R366","bundle":"https://pith.science/pith/QUNFCQJXIMTGUMUMGCD6V4R366/bundle.json","state":"https://pith.science/pith/QUNFCQJXIMTGUMUMGCD6V4R366/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QUNFCQJXIMTGUMUMGCD6V4R366/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:QUNFCQJXIMTGUMUMGCD6V4R366","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":"74811c1b72b5b7c6b5fa72101225385262bb2341132a7daff64a276b6348d40d","cross_cats_sorted":["math-ph","math.MP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-03-15T15:59:33Z","title_canon_sha256":"a1f76c5c0f030813e858977dd5815b90ce651cd4196a695d1117fa834512339e"},"schema_version":"1.0","source":{"id":"1603.04732","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1603.04732","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"arxiv_version","alias_value":"1603.04732v2","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1603.04732","created_at":"2026-05-18T01:11:48Z"},{"alias_kind":"pith_short_12","alias_value":"QUNFCQJXIMTG","created_at":"2026-05-18T12:30:41Z"},{"alias_kind":"pith_short_16","alias_value":"QUNFCQJXIMTGUMUM","created_at":"2026-05-18T12:30:41Z"},{"alias_kind":"pith_short_8","alias_value":"QUNFCQJX","created_at":"2026-05-18T12:30:41Z"}],"graph_snapshots":[{"event_id":"sha256:e3c88e56e966556112e1ce22bb2beaf03e2ca7a2181f7cadf577502355916fe9","target":"graph","created_at":"2026-05-18T01:11:48Z","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 shall introduce the principal symbol for Euler-Lagrange operators and use them to charac- terise well-posed initial value problems. We shall clarify how constraints can arise in Lagrangian covariant theories by extending the standard treatment in GR. Finally, we sketch a quantization procedure based on what done in LQG.","authors_text":"Lorenzo Fatibene, Simon Garruto","cross_cats":["math-ph","math.MP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-03-15T15:59:33Z","title":"Principal Symbol of Euler-Lagrange Operators"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1603.04732","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":"sha256:2dcb18a171f85548105ff998de7f8c4617e6ac596f2288c956a4a5b7715c8d88","target":"record","created_at":"2026-05-18T01:11:48Z","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":"74811c1b72b5b7c6b5fa72101225385262bb2341132a7daff64a276b6348d40d","cross_cats_sorted":["math-ph","math.MP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-03-15T15:59:33Z","title_canon_sha256":"a1f76c5c0f030813e858977dd5815b90ce651cd4196a695d1117fa834512339e"},"schema_version":"1.0","source":{"id":"1603.04732","kind":"arxiv","version":2}},"canonical_sha256":"851a51413743266a328c3087eaf23bf7b44291261b73942ad21f36d23a4ca3c9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"851a51413743266a328c3087eaf23bf7b44291261b73942ad21f36d23a4ca3c9","first_computed_at":"2026-05-18T01:11:48.362277Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:11:48.362277Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"1UB9kgjW0KYwn4g6Y3fIfi2AN2eII2+TE+V/DSgjR8Mr6qDaRKQd69jqVR0HvMSPU/HakTFwKHRG7lUlrd3ZBA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:11:48.362726Z","signed_message":"canonical_sha256_bytes"},"source_id":"1603.04732","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:2dcb18a171f85548105ff998de7f8c4617e6ac596f2288c956a4a5b7715c8d88","sha256:e3c88e56e966556112e1ce22bb2beaf03e2ca7a2181f7cadf577502355916fe9"],"state_sha256":"8ff2b8b5347ecfb6733ac8e5088735e170d8e1e13fbadf579d9379634f9b2db0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"+nei3LCWc3TfuVXDpBK+BExE9PgMjocPzRZ8jOnGVz6TpbvNLzhHYG3g30YGj4FV+3c/SJDUDaJbIuRacU3JCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T06:54:55.855543Z","bundle_sha256":"b9dbf24f9c52340cdae787ecaa14adab626b82dc90bdc6f942ecc1f420197ec0"}}