{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:YYIAUNNSMEP4UDYEDENBLZREUP","short_pith_number":"pith:YYIAUNNS","canonical_record":{"source":{"id":"1411.1662","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2014-11-06T17:17:36Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"db5ece0f21ad8249c4fa38c7d312f6f65160740b1cdb3396189ccf6345463bd9","abstract_canon_sha256":"1ec3b5cb4404a703887ae84a6ce3bd5ebdf5065dca44e1d2329c971973fd5fe6"},"schema_version":"1.0"},"canonical_sha256":"c6100a35b2611fca0f04191a15e624a3e9e00e2ee142062990cc6015db839006","source":{"kind":"arxiv","id":"1411.1662","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1411.1662","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"arxiv_version","alias_value":"1411.1662v3","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1411.1662","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"pith_short_12","alias_value":"YYIAUNNSMEP4","created_at":"2026-05-18T12:28:59Z"},{"alias_kind":"pith_short_16","alias_value":"YYIAUNNSMEP4UDYE","created_at":"2026-05-18T12:28:59Z"},{"alias_kind":"pith_short_8","alias_value":"YYIAUNNS","created_at":"2026-05-18T12:28:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:YYIAUNNSMEP4UDYEDENBLZREUP","target":"record","payload":{"canonical_record":{"source":{"id":"1411.1662","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2014-11-06T17:17:36Z","cross_cats_sorted":["physics.flu-dyn"],"title_canon_sha256":"db5ece0f21ad8249c4fa38c7d312f6f65160740b1cdb3396189ccf6345463bd9","abstract_canon_sha256":"1ec3b5cb4404a703887ae84a6ce3bd5ebdf5065dca44e1d2329c971973fd5fe6"},"schema_version":"1.0"},"canonical_sha256":"c6100a35b2611fca0f04191a15e624a3e9e00e2ee142062990cc6015db839006","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:55:59.837954Z","signature_b64":"rdLC0bVP/b51JKVN3cFVg4TlYusiQqOtth/8H0sVeSdCeOcesU7Z930DRyOO4XHLRxU56Bzl2DHdkLPanEXSCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c6100a35b2611fca0f04191a15e624a3e9e00e2ee142062990cc6015db839006","last_reissued_at":"2026-05-18T01:55:59.837478Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:55:59.837478Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1411.1662","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:55:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AcgoX3cgXNHlkeqR4a3pdIcBbAUugUcDldq7UKZwXXeFH53q0izSgVQg7UwxwJtGdKrxwpLKafI5eCJHiv3ZBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T16:09:25.019492Z"},"content_sha256":"a2a38b286b54059fb997b39928ce5949cb00b8ce0338742c87cc99069c632aec","schema_version":"1.0","event_id":"sha256:a2a38b286b54059fb997b39928ce5949cb00b8ce0338742c87cc99069c632aec"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:YYIAUNNSMEP4UDYEDENBLZREUP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Rotating black holes in a draining bathtub: superradiant scattering of gravity waves","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.flu-dyn"],"primary_cat":"gr-qc","authors_text":"Angus Prain, Mauricio Richartz, Silke Weinfurtner, Stefano Liberati","submitted_at":"2014-11-06T17:17:36Z","abstract_excerpt":"In a draining rotating fluid flow background, surface perturbations behave as a scalar field on a rotating effective black hole spacetime. We propose a new model for the background flow which takes into account the varying depth of the water. Numerical integration of the associated Klein-Gordon equation using accessible experimental parameters shows that gravity waves in an appropriate frequency range are amplified through the mechanism of superradiance. Our numerical results suggest that the observation of this phenomenon in a common fluid mechanical system is within experimental reach. Unlik"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.1662","kind":"arxiv","version":3},"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":"2026-05-18T01:55:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pdca+V3O5CZtD44zNgbPt/rHVirE9wTa0DG8Aw6bewJkcgmC2cK0fX/mOy+/5VXFFmJrTj5XbW3417ZbIL/xDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T16:09:25.020271Z"},"content_sha256":"f9a238d5f61eba9ac65237d540c2f5cdf3274257ba86ae179d953616b2fe125b","schema_version":"1.0","event_id":"sha256:f9a238d5f61eba9ac65237d540c2f5cdf3274257ba86ae179d953616b2fe125b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/YYIAUNNSMEP4UDYEDENBLZREUP/bundle.json","state_url":"https://pith.science/pith/YYIAUNNSMEP4UDYEDENBLZREUP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/YYIAUNNSMEP4UDYEDENBLZREUP/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":"2026-05-31T16:09:25Z","links":{"resolver":"https://pith.science/pith/YYIAUNNSMEP4UDYEDENBLZREUP","bundle":"https://pith.science/pith/YYIAUNNSMEP4UDYEDENBLZREUP/bundle.json","state":"https://pith.science/pith/YYIAUNNSMEP4UDYEDENBLZREUP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/YYIAUNNSMEP4UDYEDENBLZREUP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:YYIAUNNSMEP4UDYEDENBLZREUP","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":"1ec3b5cb4404a703887ae84a6ce3bd5ebdf5065dca44e1d2329c971973fd5fe6","cross_cats_sorted":["physics.flu-dyn"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2014-11-06T17:17:36Z","title_canon_sha256":"db5ece0f21ad8249c4fa38c7d312f6f65160740b1cdb3396189ccf6345463bd9"},"schema_version":"1.0","source":{"id":"1411.1662","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1411.1662","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"arxiv_version","alias_value":"1411.1662v3","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1411.1662","created_at":"2026-05-18T01:55:59Z"},{"alias_kind":"pith_short_12","alias_value":"YYIAUNNSMEP4","created_at":"2026-05-18T12:28:59Z"},{"alias_kind":"pith_short_16","alias_value":"YYIAUNNSMEP4UDYE","created_at":"2026-05-18T12:28:59Z"},{"alias_kind":"pith_short_8","alias_value":"YYIAUNNS","created_at":"2026-05-18T12:28:59Z"}],"graph_snapshots":[{"event_id":"sha256:f9a238d5f61eba9ac65237d540c2f5cdf3274257ba86ae179d953616b2fe125b","target":"graph","created_at":"2026-05-18T01:55:59Z","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"},"paper":{"abstract_excerpt":"In a draining rotating fluid flow background, surface perturbations behave as a scalar field on a rotating effective black hole spacetime. We propose a new model for the background flow which takes into account the varying depth of the water. Numerical integration of the associated Klein-Gordon equation using accessible experimental parameters shows that gravity waves in an appropriate frequency range are amplified through the mechanism of superradiance. Our numerical results suggest that the observation of this phenomenon in a common fluid mechanical system is within experimental reach. Unlik","authors_text":"Angus Prain, Mauricio Richartz, Silke Weinfurtner, Stefano Liberati","cross_cats":["physics.flu-dyn"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2014-11-06T17:17:36Z","title":"Rotating black holes in a draining bathtub: superradiant scattering of gravity waves"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.1662","kind":"arxiv","version":3},"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:a2a38b286b54059fb997b39928ce5949cb00b8ce0338742c87cc99069c632aec","target":"record","created_at":"2026-05-18T01:55:59Z","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":"1ec3b5cb4404a703887ae84a6ce3bd5ebdf5065dca44e1d2329c971973fd5fe6","cross_cats_sorted":["physics.flu-dyn"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2014-11-06T17:17:36Z","title_canon_sha256":"db5ece0f21ad8249c4fa38c7d312f6f65160740b1cdb3396189ccf6345463bd9"},"schema_version":"1.0","source":{"id":"1411.1662","kind":"arxiv","version":3}},"canonical_sha256":"c6100a35b2611fca0f04191a15e624a3e9e00e2ee142062990cc6015db839006","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c6100a35b2611fca0f04191a15e624a3e9e00e2ee142062990cc6015db839006","first_computed_at":"2026-05-18T01:55:59.837478Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:55:59.837478Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"rdLC0bVP/b51JKVN3cFVg4TlYusiQqOtth/8H0sVeSdCeOcesU7Z930DRyOO4XHLRxU56Bzl2DHdkLPanEXSCw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:55:59.837954Z","signed_message":"canonical_sha256_bytes"},"source_id":"1411.1662","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a2a38b286b54059fb997b39928ce5949cb00b8ce0338742c87cc99069c632aec","sha256:f9a238d5f61eba9ac65237d540c2f5cdf3274257ba86ae179d953616b2fe125b"],"state_sha256":"9b2ee3872bdd2402a749dc0aade63d88eadf50d0c317b423e2e63a10888ee369"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LlvpIOyCUmdJ8yuVkhi4KN+6RxowIKe9a/hLvtqBtZwgZyko+NeLCdrIary/B1Vfgl/JhVPsxixuXFpcGsd3Cg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T16:09:25.024358Z","bundle_sha256":"f3fc081f9d20408099773b750843a64c8505eab293e72bcd91e25c121aa708b1"}}