{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:1998:SCV4T7QVZB2GBFSKMBHPFFQDCE","short_pith_number":"pith:SCV4T7QV","canonical_record":{"source":{"id":"gr-qc/9807081","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"gr-qc","submitted_at":"1998-07-29T14:25:29Z","cross_cats_sorted":[],"title_canon_sha256":"31a7b5eb0d145fce5c4ac75d91fa1c0ee4e55a71ba94ced9a67de3cca2d6aa8d","abstract_canon_sha256":"835e56f5c6c096f375eb80ec94b5ff954c5461ea99fc8db452d7624006230721"},"schema_version":"1.0"},"canonical_sha256":"90abc9fe15c87460964a604ef29603113605c2448f59843cdb3f6da36b1ad3c3","source":{"kind":"arxiv","id":"gr-qc/9807081","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"gr-qc/9807081","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"arxiv_version","alias_value":"gr-qc/9807081v1","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.gr-qc/9807081","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_12","alias_value":"SCV4T7QVZB2G","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_16","alias_value":"SCV4T7QVZB2GBFSK","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_8","alias_value":"SCV4T7QV","created_at":"2026-07-04T16:08:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:1998:SCV4T7QVZB2GBFSKMBHPFFQDCE","target":"record","payload":{"canonical_record":{"source":{"id":"gr-qc/9807081","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"gr-qc","submitted_at":"1998-07-29T14:25:29Z","cross_cats_sorted":[],"title_canon_sha256":"31a7b5eb0d145fce5c4ac75d91fa1c0ee4e55a71ba94ced9a67de3cca2d6aa8d","abstract_canon_sha256":"835e56f5c6c096f375eb80ec94b5ff954c5461ea99fc8db452d7624006230721"},"schema_version":"1.0"},"canonical_sha256":"90abc9fe15c87460964a604ef29603113605c2448f59843cdb3f6da36b1ad3c3","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T16:08:50.734701Z","signature_b64":"yRM96igENfiCyYgmDsrvVFAqrxAEgpq9Byh0M6LjA3pafJCZXyWU7ljZJ/YD3GxIGMfqLLbxeAFmkRlaKVtEAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"90abc9fe15c87460964a604ef29603113605c2448f59843cdb3f6da36b1ad3c3","last_reissued_at":"2026-07-04T16:08:50.734322Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T16:08:50.734322Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"gr-qc/9807081","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":"2026-07-04T16:08:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Rgz98sxScnjcsjiHBW9PfhQ30yrrb1LyflElz7a/erCPdo1pkPEwvLcKeOhctxf2C2Fhx9qnR6z89JjJ4pXmCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-11T05:22:12.643669Z"},"content_sha256":"2a077e002fa49b7e4085af1a307ccd1fe82fcacd05a6a78993df07083816fcf5","schema_version":"1.0","event_id":"sha256:2a077e002fa49b7e4085af1a307ccd1fe82fcacd05a6a78993df07083816fcf5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:1998:SCV4T7QVZB2GBFSKMBHPFFQDCE","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Non-expanding impulsive gravitational waves","license":"","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"J. Podolsky","submitted_at":"1998-07-29T14:25:29Z","abstract_excerpt":"We investigate a class of impulsive gravitational waves which propagate either in Minkowski or in the (anti-)de Sitter background. These waves are constructed as impulsive members of the Kundt class $P(\\Lambda)$ of non-twisting, non-expanding type N solutions of vacuum Einstein equations with a cosmological constant $\\Lambda$. We show that the only non-trivial waves of this type in Minkowski spacetime are impulsive pp-waves. For $\\Lambda\\not=0$ we demonstrate that the canonical subclasses of $P(\\Lambda)$, which are invariantly different for smooth profiles, are all locally equivalent for impul"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"gr-qc/9807081","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/gr-qc/9807081/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":"2026-07-04T16:08:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lIMpFEGxWkQt1MVXYOGYNqqmcyA6AXnC/bfIdKxLWqdYZWr+Qe2xKe5BN5xVRHNq4/I5TPiwqCR7ZTcUBQmzDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-11T05:22:12.644232Z"},"content_sha256":"194bee6961f697c0b6cd011c56718e8990004288e03ca67f3c93c9264b67104e","schema_version":"1.0","event_id":"sha256:194bee6961f697c0b6cd011c56718e8990004288e03ca67f3c93c9264b67104e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/bundle.json","state_url":"https://pith.science/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/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":"2026-08-11T05:22:12Z","links":{"resolver":"https://pith.science/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE","bundle":"https://pith.science/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/bundle.json","state":"https://pith.science/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/state.json","well_known_bundle":"https://pith.science/.well-known/pith/SCV4T7QVZB2GBFSKMBHPFFQDCE/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1998:SCV4T7QVZB2GBFSKMBHPFFQDCE","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":"835e56f5c6c096f375eb80ec94b5ff954c5461ea99fc8db452d7624006230721","cross_cats_sorted":[],"license":"","primary_cat":"gr-qc","submitted_at":"1998-07-29T14:25:29Z","title_canon_sha256":"31a7b5eb0d145fce5c4ac75d91fa1c0ee4e55a71ba94ced9a67de3cca2d6aa8d"},"schema_version":"1.0","source":{"id":"gr-qc/9807081","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"gr-qc/9807081","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"arxiv_version","alias_value":"gr-qc/9807081v1","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.gr-qc/9807081","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_12","alias_value":"SCV4T7QVZB2G","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_16","alias_value":"SCV4T7QVZB2GBFSK","created_at":"2026-07-04T16:08:50Z"},{"alias_kind":"pith_short_8","alias_value":"SCV4T7QV","created_at":"2026-07-04T16:08:50Z"}],"graph_snapshots":[{"event_id":"sha256:194bee6961f697c0b6cd011c56718e8990004288e03ca67f3c93c9264b67104e","target":"graph","created_at":"2026-07-04T16:08:50Z","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/gr-qc/9807081/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We investigate a class of impulsive gravitational waves which propagate either in Minkowski or in the (anti-)de Sitter background. These waves are constructed as impulsive members of the Kundt class $P(\\Lambda)$ of non-twisting, non-expanding type N solutions of vacuum Einstein equations with a cosmological constant $\\Lambda$. We show that the only non-trivial waves of this type in Minkowski spacetime are impulsive pp-waves. For $\\Lambda\\not=0$ we demonstrate that the canonical subclasses of $P(\\Lambda)$, which are invariantly different for smooth profiles, are all locally equivalent for impul","authors_text":"J. Podolsky","cross_cats":[],"headline":"","license":"","primary_cat":"gr-qc","submitted_at":"1998-07-29T14:25:29Z","title":"Non-expanding impulsive gravitational waves"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"gr-qc/9807081","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":"sha256:2a077e002fa49b7e4085af1a307ccd1fe82fcacd05a6a78993df07083816fcf5","target":"record","created_at":"2026-07-04T16:08:50Z","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":"835e56f5c6c096f375eb80ec94b5ff954c5461ea99fc8db452d7624006230721","cross_cats_sorted":[],"license":"","primary_cat":"gr-qc","submitted_at":"1998-07-29T14:25:29Z","title_canon_sha256":"31a7b5eb0d145fce5c4ac75d91fa1c0ee4e55a71ba94ced9a67de3cca2d6aa8d"},"schema_version":"1.0","source":{"id":"gr-qc/9807081","kind":"arxiv","version":1}},"canonical_sha256":"90abc9fe15c87460964a604ef29603113605c2448f59843cdb3f6da36b1ad3c3","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"90abc9fe15c87460964a604ef29603113605c2448f59843cdb3f6da36b1ad3c3","first_computed_at":"2026-07-04T16:08:50.734322Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T16:08:50.734322Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"yRM96igENfiCyYgmDsrvVFAqrxAEgpq9Byh0M6LjA3pafJCZXyWU7ljZJ/YD3GxIGMfqLLbxeAFmkRlaKVtEAw==","signature_status":"signed_v1","signed_at":"2026-07-04T16:08:50.734701Z","signed_message":"canonical_sha256_bytes"},"source_id":"gr-qc/9807081","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:2a077e002fa49b7e4085af1a307ccd1fe82fcacd05a6a78993df07083816fcf5","sha256:194bee6961f697c0b6cd011c56718e8990004288e03ca67f3c93c9264b67104e"],"state_sha256":"9cce945263ae9e788a3194dbb6d3d381f6f327de3abe7f273da04eab8e82049d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FnrMw1Th1SuC3cRvwH4yLbJsE5VrNCSzaAPl1NIChLh0F/I+e36gJ1WeoU4mAnQEbR7HmNSJzMI/2KmgDSqJBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-11T05:22:12.649764Z","bundle_sha256":"646b794e15e3eb55f5340ec6e97629637809a35c019c0ffc31116fa881b8f8db"}}