{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:LPVWRKPDNVRPLI2ERARRQA2SEY","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":"6578576c5db305a5f4f4f15ccc9beb3d34b1cf8f00e60a881dc4bc5d43a15bea","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2020-07-08T18:46:15Z","title_canon_sha256":"085482b8a37cc38719da0280baac74e32767f0829b116d19bb9802cfad0cabfd"},"schema_version":"1.0","source":{"id":"2007.04365","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2007.04365","created_at":"2026-07-05T01:46:59Z"},{"alias_kind":"arxiv_version","alias_value":"2007.04365v1","created_at":"2026-07-05T01:46:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2007.04365","created_at":"2026-07-05T01:46:59Z"},{"alias_kind":"pith_short_12","alias_value":"LPVWRKPDNVRP","created_at":"2026-07-05T01:46:59Z"},{"alias_kind":"pith_short_16","alias_value":"LPVWRKPDNVRPLI2E","created_at":"2026-07-05T01:46:59Z"},{"alias_kind":"pith_short_8","alias_value":"LPVWRKPD","created_at":"2026-07-05T01:46:59Z"}],"graph_snapshots":[{"event_id":"sha256:73313f5f2178232ba21b81fd52fc948b469cf6b50599c02f40eb013d53a6c06e","target":"graph","created_at":"2026-07-05T01:46:59Z","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/2007.04365/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In this study, we connect concepts that have been recently developed in thermoacoustics, specifically, (i) high-order spectral perturbation theory, (ii) symmetry induced degenerate thermoacoustic modes, (iii) intrinsic thermoacoustic modes, and (iv) exceptional points. Their connection helps gain physical insight into the behaviour of the thermoacoustic spectrum when parameters of the system are varied. First, we extend high-order adjoint-based perturbation theory of thermoacoustic modes to the degenerate case. We provide explicit formulae for the calculation of the eigenvalue corrections to a","authors_text":"Alessandro Orchini, Camilo F. Silva, Georg A. Mensah, Jonas P. Moeck, Luca Magri","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2020-07-08T18:46:15Z","title":"Degenerate perturbation theory in thermoacoustics: high-order sensitivities and exceptional points"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2007.04365","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:b9246674aca41bb537f83dbb06b358d61af6f0a06c8f3c7e0be70bc961efcfe2","target":"record","created_at":"2026-07-05T01:46:59Z","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":"6578576c5db305a5f4f4f15ccc9beb3d34b1cf8f00e60a881dc4bc5d43a15bea","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2020-07-08T18:46:15Z","title_canon_sha256":"085482b8a37cc38719da0280baac74e32767f0829b116d19bb9802cfad0cabfd"},"schema_version":"1.0","source":{"id":"2007.04365","kind":"arxiv","version":1}},"canonical_sha256":"5beb68a9e36d62f5a3448823180352261fdc66f588568188801e571ab0e587cd","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5beb68a9e36d62f5a3448823180352261fdc66f588568188801e571ab0e587cd","first_computed_at":"2026-07-05T01:46:59.188715Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:46:59.188715Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"tTMg1emfNIfA4GU71DxWUSHSyrXU8Zv0bwAC3nf81gTV9Ai2dVxt0o0aeybOyxKcciNOSCTu7kz4NPFZfRJnAw==","signature_status":"signed_v1","signed_at":"2026-07-05T01:46:59.189193Z","signed_message":"canonical_sha256_bytes"},"source_id":"2007.04365","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b9246674aca41bb537f83dbb06b358d61af6f0a06c8f3c7e0be70bc961efcfe2","sha256:73313f5f2178232ba21b81fd52fc948b469cf6b50599c02f40eb013d53a6c06e"],"state_sha256":"54888964fa41dffb71a5548de628ea01eb8e28b9c6aa4a8f65097f20df3e2eeb"}