{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:FIVL5DGCOKV5CZGHLAK32V3YAV","short_pith_number":"pith:FIVL5DGC","canonical_record":{"source":{"id":"1612.06715","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-12-20T15:45:32Z","cross_cats_sorted":[],"title_canon_sha256":"a543de394de84fac2d7833e1ec58e9d9d72afa1e5bb88527ef7887c0d92c5948","abstract_canon_sha256":"9e422f340216a05536b2ff8f7ef80acdc3a4f3c3911d7bd5ee0e766bdd76d6f5"},"schema_version":"1.0"},"canonical_sha256":"2a2abe8cc272abd164c75815bd5778057209cd7980ba7c793fed0853e825091a","source":{"kind":"arxiv","id":"1612.06715","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1612.06715","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"arxiv_version","alias_value":"1612.06715v2","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1612.06715","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"pith_short_12","alias_value":"FIVL5DGCOKV5","created_at":"2026-05-18T12:30:15Z"},{"alias_kind":"pith_short_16","alias_value":"FIVL5DGCOKV5CZGH","created_at":"2026-05-18T12:30:15Z"},{"alias_kind":"pith_short_8","alias_value":"FIVL5DGC","created_at":"2026-05-18T12:30:15Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:FIVL5DGCOKV5CZGHLAK32V3YAV","target":"record","payload":{"canonical_record":{"source":{"id":"1612.06715","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-12-20T15:45:32Z","cross_cats_sorted":[],"title_canon_sha256":"a543de394de84fac2d7833e1ec58e9d9d72afa1e5bb88527ef7887c0d92c5948","abstract_canon_sha256":"9e422f340216a05536b2ff8f7ef80acdc3a4f3c3911d7bd5ee0e766bdd76d6f5"},"schema_version":"1.0"},"canonical_sha256":"2a2abe8cc272abd164c75815bd5778057209cd7980ba7c793fed0853e825091a","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:45:53.607504Z","signature_b64":"MWzKwPAPfJmILnXMoSYgmVNAIw5T2ANvBFSwx2Kv442c7FypO0+kGI1W37JoRhAcU97OgethXB+eJxw+ave2CQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2a2abe8cc272abd164c75815bd5778057209cd7980ba7c793fed0853e825091a","last_reissued_at":"2026-05-17T23:45:53.607094Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:45:53.607094Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1612.06715","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":"2026-05-17T23:45:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GQnI9ERm9IhSixnNpsZGPPLljeCAOPxWxojXTsiY3YmBzgUE2+UKjDjhRvWpY18qsJB3aTBULI6GfTpkFgVqDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T11:52:21.750273Z"},"content_sha256":"9292c6727f92b07816db5fce8456096393d35799ba8def03c12fd76737d20209","schema_version":"1.0","event_id":"sha256:9292c6727f92b07816db5fce8456096393d35799ba8def03c12fd76737d20209"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:FIVL5DGCOKV5CZGHLAK32V3YAV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Twisted Lorentzian manifolds, a characterization with torse-forming time-like unit vectors","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"Carlo Alberto Mantica, Luca Guido Molinari","submitted_at":"2016-12-20T15:45:32Z","abstract_excerpt":"Robertson-Walker and Generalized Robertson-Walker spacetimes may be characterized by the existence of a time-like unit torse-forming vector field, with other constrains. We show that Twisted manifolds may still be characterized by the existence of such (unique) vector field, with no other constrain. Twisted manifolds generalize RW and GRW spacetimes by admitting a scale function that depends both on time and space. We obtain the Ricci tensor, corresponding to the stress-energy tensor of an imperfect fluid."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1612.06715","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":"2026-05-17T23:45:53Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0FHbrQ2sqBgqWabmdN37wu/sSeVNcz/D46TI34LATiSEDZ/TUj2JHY9pE5SbD2e9NhjRHCbjmsF8DBt4V4wbAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T11:52:21.750635Z"},"content_sha256":"76d71642304ccdd78a30c2d0e8d7c87018be161422099d487d4f3bcccf9b5ed6","schema_version":"1.0","event_id":"sha256:76d71642304ccdd78a30c2d0e8d7c87018be161422099d487d4f3bcccf9b5ed6"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/bundle.json","state_url":"https://pith.science/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/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":"2026-06-05T11:52:21Z","links":{"resolver":"https://pith.science/pith/FIVL5DGCOKV5CZGHLAK32V3YAV","bundle":"https://pith.science/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/bundle.json","state":"https://pith.science/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/FIVL5DGCOKV5CZGHLAK32V3YAV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:FIVL5DGCOKV5CZGHLAK32V3YAV","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":"9e422f340216a05536b2ff8f7ef80acdc3a4f3c3911d7bd5ee0e766bdd76d6f5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-12-20T15:45:32Z","title_canon_sha256":"a543de394de84fac2d7833e1ec58e9d9d72afa1e5bb88527ef7887c0d92c5948"},"schema_version":"1.0","source":{"id":"1612.06715","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1612.06715","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"arxiv_version","alias_value":"1612.06715v2","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1612.06715","created_at":"2026-05-17T23:45:53Z"},{"alias_kind":"pith_short_12","alias_value":"FIVL5DGCOKV5","created_at":"2026-05-18T12:30:15Z"},{"alias_kind":"pith_short_16","alias_value":"FIVL5DGCOKV5CZGH","created_at":"2026-05-18T12:30:15Z"},{"alias_kind":"pith_short_8","alias_value":"FIVL5DGC","created_at":"2026-05-18T12:30:15Z"}],"graph_snapshots":[{"event_id":"sha256:76d71642304ccdd78a30c2d0e8d7c87018be161422099d487d4f3bcccf9b5ed6","target":"graph","created_at":"2026-05-17T23:45:53Z","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":"Robertson-Walker and Generalized Robertson-Walker spacetimes may be characterized by the existence of a time-like unit torse-forming vector field, with other constrains. We show that Twisted manifolds may still be characterized by the existence of such (unique) vector field, with no other constrain. Twisted manifolds generalize RW and GRW spacetimes by admitting a scale function that depends both on time and space. We obtain the Ricci tensor, corresponding to the stress-energy tensor of an imperfect fluid.","authors_text":"Carlo Alberto Mantica, Luca Guido Molinari","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-12-20T15:45:32Z","title":"Twisted Lorentzian manifolds, a characterization with torse-forming time-like unit vectors"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1612.06715","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":"sha256:9292c6727f92b07816db5fce8456096393d35799ba8def03c12fd76737d20209","target":"record","created_at":"2026-05-17T23:45:53Z","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":"9e422f340216a05536b2ff8f7ef80acdc3a4f3c3911d7bd5ee0e766bdd76d6f5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"gr-qc","submitted_at":"2016-12-20T15:45:32Z","title_canon_sha256":"a543de394de84fac2d7833e1ec58e9d9d72afa1e5bb88527ef7887c0d92c5948"},"schema_version":"1.0","source":{"id":"1612.06715","kind":"arxiv","version":2}},"canonical_sha256":"2a2abe8cc272abd164c75815bd5778057209cd7980ba7c793fed0853e825091a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2a2abe8cc272abd164c75815bd5778057209cd7980ba7c793fed0853e825091a","first_computed_at":"2026-05-17T23:45:53.607094Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:45:53.607094Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MWzKwPAPfJmILnXMoSYgmVNAIw5T2ANvBFSwx2Kv442c7FypO0+kGI1W37JoRhAcU97OgethXB+eJxw+ave2CQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:45:53.607504Z","signed_message":"canonical_sha256_bytes"},"source_id":"1612.06715","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9292c6727f92b07816db5fce8456096393d35799ba8def03c12fd76737d20209","sha256:76d71642304ccdd78a30c2d0e8d7c87018be161422099d487d4f3bcccf9b5ed6"],"state_sha256":"eb8a5ee057136fbdf3943e23bfd16ebf7c0bf35a4b1c2adfdd0a504013825278"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"twIXJGbCEB8CfH5gz5IFB7HF+0ZFZacTv5yHtebqXBNpdmt53ixMs2M6QGdfbFEdzXW8EPufsLphe/GFF670AQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-05T11:52:21.752719Z","bundle_sha256":"0aeec16fc8956fd9e261f6256be6dd1a806849ff40f355e97fec4b7dd31b8ce9"}}