{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:V6IEY5FPMBUJDSJ7TD25QC65GI","short_pith_number":"pith:V6IEY5FP","canonical_record":{"source":{"id":"1504.07625","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2015-04-28T17:33:17Z","cross_cats_sorted":[],"title_canon_sha256":"2e2727da820690ac3a7f63a84e451de7401a96214a77d63ca829e5fa03de00af","abstract_canon_sha256":"c87229173deda1ba3efa518fced544e069bcdd857c128bb8a0a5c928ab227bd4"},"schema_version":"1.0"},"canonical_sha256":"af904c74af606891c93f98f5d80bdd321ca6eafb1d19ed922c257b984199c927","source":{"kind":"arxiv","id":"1504.07625","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1504.07625","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"arxiv_version","alias_value":"1504.07625v1","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1504.07625","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"pith_short_12","alias_value":"V6IEY5FPMBUJ","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_16","alias_value":"V6IEY5FPMBUJDSJ7","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_8","alias_value":"V6IEY5FP","created_at":"2026-05-18T12:29:44Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:V6IEY5FPMBUJDSJ7TD25QC65GI","target":"record","payload":{"canonical_record":{"source":{"id":"1504.07625","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2015-04-28T17:33:17Z","cross_cats_sorted":[],"title_canon_sha256":"2e2727da820690ac3a7f63a84e451de7401a96214a77d63ca829e5fa03de00af","abstract_canon_sha256":"c87229173deda1ba3efa518fced544e069bcdd857c128bb8a0a5c928ab227bd4"},"schema_version":"1.0"},"canonical_sha256":"af904c74af606891c93f98f5d80bdd321ca6eafb1d19ed922c257b984199c927","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:17:32.728176Z","signature_b64":"/WtdrT98svGag2ZivoBDGQmNZfAXnv6UyCHQqOM09X5tNCSgMX8RFbxR0t4auvLkU9ACd6FCPJ9G4h227Ko6Ag==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"af904c74af606891c93f98f5d80bdd321ca6eafb1d19ed922c257b984199c927","last_reissued_at":"2026-05-18T02:17:32.727365Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:17:32.727365Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1504.07625","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":"2026-05-18T02:17:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bEPhi4wYCfMrbrvHqONWfEDsO9Ir6eRlAUYq876vv3KYw5ravtVwEZqI3sVTfLiJsYL13+dCTnai2ZXHYKiYDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T06:54:44.836829Z"},"content_sha256":"6322257cc27d81bcbe6e28865dc7db5b460b249fef2fb2c753bfe2446eee8738","schema_version":"1.0","event_id":"sha256:6322257cc27d81bcbe6e28865dc7db5b460b249fef2fb2c753bfe2446eee8738"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:V6IEY5FPMBUJDSJ7TD25QC65GI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Karlqvist approximation revisited","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.class-ph","authors_text":"C. Tannous","submitted_at":"2015-04-28T17:33:17Z","abstract_excerpt":"The Karlqvist approximation signaling the historical beginning of magnetic recording head theory is reviewed and compared to various approaches progressing from Green, Fourier, Conformal mapping that obeys the Sommerfeld edge condition at angular points and leads to exact results."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1504.07625","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":""},"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":"2026-05-18T02:17:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"r/jtbktyJCmPn9nYNAy1M1/DiAArmzJZvywu3hb1s86HTCSy1LqgloojDZAh0tunnrv/xZF8jrzAQw6oaON/Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T06:54:44.837184Z"},"content_sha256":"13cb34feaecdd7d75c310be99ff0b4722a42c97ee81969d60f6835683ecffac3","schema_version":"1.0","event_id":"sha256:13cb34feaecdd7d75c310be99ff0b4722a42c97ee81969d60f6835683ecffac3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/bundle.json","state_url":"https://pith.science/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/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":"2026-06-01T06:54:44Z","links":{"resolver":"https://pith.science/pith/V6IEY5FPMBUJDSJ7TD25QC65GI","bundle":"https://pith.science/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/bundle.json","state":"https://pith.science/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/V6IEY5FPMBUJDSJ7TD25QC65GI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:V6IEY5FPMBUJDSJ7TD25QC65GI","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":"c87229173deda1ba3efa518fced544e069bcdd857c128bb8a0a5c928ab227bd4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2015-04-28T17:33:17Z","title_canon_sha256":"2e2727da820690ac3a7f63a84e451de7401a96214a77d63ca829e5fa03de00af"},"schema_version":"1.0","source":{"id":"1504.07625","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1504.07625","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"arxiv_version","alias_value":"1504.07625v1","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1504.07625","created_at":"2026-05-18T02:17:32Z"},{"alias_kind":"pith_short_12","alias_value":"V6IEY5FPMBUJ","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_16","alias_value":"V6IEY5FPMBUJDSJ7","created_at":"2026-05-18T12:29:44Z"},{"alias_kind":"pith_short_8","alias_value":"V6IEY5FP","created_at":"2026-05-18T12:29:44Z"}],"graph_snapshots":[{"event_id":"sha256:13cb34feaecdd7d75c310be99ff0b4722a42c97ee81969d60f6835683ecffac3","target":"graph","created_at":"2026-05-18T02:17:32Z","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":"The Karlqvist approximation signaling the historical beginning of magnetic recording head theory is reviewed and compared to various approaches progressing from Green, Fourier, Conformal mapping that obeys the Sommerfeld edge condition at angular points and leads to exact results.","authors_text":"C. Tannous","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2015-04-28T17:33:17Z","title":"The Karlqvist approximation revisited"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1504.07625","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":"sha256:6322257cc27d81bcbe6e28865dc7db5b460b249fef2fb2c753bfe2446eee8738","target":"record","created_at":"2026-05-18T02:17:32Z","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":"c87229173deda1ba3efa518fced544e069bcdd857c128bb8a0a5c928ab227bd4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2015-04-28T17:33:17Z","title_canon_sha256":"2e2727da820690ac3a7f63a84e451de7401a96214a77d63ca829e5fa03de00af"},"schema_version":"1.0","source":{"id":"1504.07625","kind":"arxiv","version":1}},"canonical_sha256":"af904c74af606891c93f98f5d80bdd321ca6eafb1d19ed922c257b984199c927","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"af904c74af606891c93f98f5d80bdd321ca6eafb1d19ed922c257b984199c927","first_computed_at":"2026-05-18T02:17:32.727365Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:17:32.727365Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"/WtdrT98svGag2ZivoBDGQmNZfAXnv6UyCHQqOM09X5tNCSgMX8RFbxR0t4auvLkU9ACd6FCPJ9G4h227Ko6Ag==","signature_status":"signed_v1","signed_at":"2026-05-18T02:17:32.728176Z","signed_message":"canonical_sha256_bytes"},"source_id":"1504.07625","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6322257cc27d81bcbe6e28865dc7db5b460b249fef2fb2c753bfe2446eee8738","sha256:13cb34feaecdd7d75c310be99ff0b4722a42c97ee81969d60f6835683ecffac3"],"state_sha256":"b7a7c5f887528127f9eba38d8ab25b9a36432429ac4d6a352af6fb571f0aa1e2"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HuLVp9Me5eiYWNkY9tk0VR0Ik9yRfqpWKiG+gzEgiEqMbAb3bRvmx6WZDwXderBQ9+LWvxoiHDiUn552TrDFAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T06:54:44.839600Z","bundle_sha256":"733ab296a567a33b4b6a5cfbf1377ce5f179aff4eaaf26f17e82c05828cd54dd"}}