{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:KQ4DL2QA34D7Z63QCINIJ5XA7I","short_pith_number":"pith:KQ4DL2QA","canonical_record":{"source":{"id":"2002.03638","kind":"arxiv","version":4},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"q-bio.PE","submitted_at":"2020-02-10T10:36:26Z","cross_cats_sorted":[],"title_canon_sha256":"b0942300680a55aa2eff2c06bad1745ee148ec0fd1d82bf17a9e75b83ca26e50","abstract_canon_sha256":"cb4dc034ae343054b57fdcad48912c1aa95ed49831a9d709c58dde21280a2ca9"},"schema_version":"1.0"},"canonical_sha256":"543835ea00df07fcfb70121a84f6e0fa0c560b838a61a4cf4b8390da34ffda7d","source":{"kind":"arxiv","id":"2002.03638","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2002.03638","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"arxiv_version","alias_value":"2002.03638v4","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2002.03638","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_12","alias_value":"KQ4DL2QA34D7","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_16","alias_value":"KQ4DL2QA34D7Z63Q","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_8","alias_value":"KQ4DL2QA","created_at":"2026-07-05T01:36:28Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:KQ4DL2QA34D7Z63QCINIJ5XA7I","target":"record","payload":{"canonical_record":{"source":{"id":"2002.03638","kind":"arxiv","version":4},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"q-bio.PE","submitted_at":"2020-02-10T10:36:26Z","cross_cats_sorted":[],"title_canon_sha256":"b0942300680a55aa2eff2c06bad1745ee148ec0fd1d82bf17a9e75b83ca26e50","abstract_canon_sha256":"cb4dc034ae343054b57fdcad48912c1aa95ed49831a9d709c58dde21280a2ca9"},"schema_version":"1.0"},"canonical_sha256":"543835ea00df07fcfb70121a84f6e0fa0c560b838a61a4cf4b8390da34ffda7d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:36:28.480554Z","signature_b64":"zOPV4sN2S+bhLxz60hmdHlGU9W9SVnKR43W6f2UetQYgqXmAvWq4fGksJnugjZBTvL5X9sSof+a/idUy7BLBAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"543835ea00df07fcfb70121a84f6e0fa0c560b838a61a4cf4b8390da34ffda7d","last_reissued_at":"2026-07-05T01:36:28.480061Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:36:28.480061Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2002.03638","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:36:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hEZKZ62DUlJqcjIHchYb5rxffBeMLUd1v96ylp6o6sUQvexSiq9/BRm5h2rJFMAzyOpChZRDSn0/9QKTMdWmDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-15T10:52:20.746995Z"},"content_sha256":"ff62d86c5ee57ed3eff96cc77fdbf69d159e7c341ff27a1f3ce42fe3d04828c9","schema_version":"1.0","event_id":"sha256:ff62d86c5ee57ed3eff96cc77fdbf69d159e7c341ff27a1f3ce42fe3d04828c9"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:KQ4DL2QA34D7Z63QCINIJ5XA7I","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Piecewise quadratic growth during the 2019 novel coronavirus epidemic","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"q-bio.PE","authors_text":"Axel Brandenburg","submitted_at":"2020-02-10T10:36:26Z","abstract_excerpt":"The temporal growth in the number of deaths in the COVID-19 epidemic is subexponential. Here we show that a piecewise quadratic law provides an excellent fit during the thirty days after the first three fatalities on January 20 and later since the end of March 2020. There is also a brief intermediate period of exponential growth. During the second quadratic growth phase, the characteristic time of the growth is about eight times shorter than in the beginning, which can be understood as the occurrence of separate hotspots. Quadratic behavior can be motivated by peripheral growth when further sp"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2002.03638","kind":"arxiv","version":4},"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/2002.03638/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":"2026-07-05T01:36:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n4+PbQYNmqneiPQZX88wb5F7hdhuYs7I1TC55sY2fSv6Av/+OC3uqLH8xoOS+quX4q90qiYRWjx3RSeQ5IL0Bw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-15T10:52:20.747569Z"},"content_sha256":"67ea80d7879ee06386a288527fa7e2ce18f0b772b22985ad240d5bf820c80927","schema_version":"1.0","event_id":"sha256:67ea80d7879ee06386a288527fa7e2ce18f0b772b22985ad240d5bf820c80927"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/bundle.json","state_url":"https://pith.science/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/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":"2026-08-15T10:52:20Z","links":{"resolver":"https://pith.science/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I","bundle":"https://pith.science/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/bundle.json","state":"https://pith.science/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/state.json","well_known_bundle":"https://pith.science/.well-known/pith/KQ4DL2QA34D7Z63QCINIJ5XA7I/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:KQ4DL2QA34D7Z63QCINIJ5XA7I","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":"cb4dc034ae343054b57fdcad48912c1aa95ed49831a9d709c58dde21280a2ca9","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"q-bio.PE","submitted_at":"2020-02-10T10:36:26Z","title_canon_sha256":"b0942300680a55aa2eff2c06bad1745ee148ec0fd1d82bf17a9e75b83ca26e50"},"schema_version":"1.0","source":{"id":"2002.03638","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2002.03638","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"arxiv_version","alias_value":"2002.03638v4","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2002.03638","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_12","alias_value":"KQ4DL2QA34D7","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_16","alias_value":"KQ4DL2QA34D7Z63Q","created_at":"2026-07-05T01:36:28Z"},{"alias_kind":"pith_short_8","alias_value":"KQ4DL2QA","created_at":"2026-07-05T01:36:28Z"}],"graph_snapshots":[{"event_id":"sha256:67ea80d7879ee06386a288527fa7e2ce18f0b772b22985ad240d5bf820c80927","target":"graph","created_at":"2026-07-05T01:36:28Z","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/2002.03638/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The temporal growth in the number of deaths in the COVID-19 epidemic is subexponential. Here we show that a piecewise quadratic law provides an excellent fit during the thirty days after the first three fatalities on January 20 and later since the end of March 2020. There is also a brief intermediate period of exponential growth. During the second quadratic growth phase, the characteristic time of the growth is about eight times shorter than in the beginning, which can be understood as the occurrence of separate hotspots. Quadratic behavior can be motivated by peripheral growth when further sp","authors_text":"Axel Brandenburg","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"q-bio.PE","submitted_at":"2020-02-10T10:36:26Z","title":"Piecewise quadratic growth during the 2019 novel coronavirus epidemic"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2002.03638","kind":"arxiv","version":4},"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:ff62d86c5ee57ed3eff96cc77fdbf69d159e7c341ff27a1f3ce42fe3d04828c9","target":"record","created_at":"2026-07-05T01:36:28Z","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":"cb4dc034ae343054b57fdcad48912c1aa95ed49831a9d709c58dde21280a2ca9","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"q-bio.PE","submitted_at":"2020-02-10T10:36:26Z","title_canon_sha256":"b0942300680a55aa2eff2c06bad1745ee148ec0fd1d82bf17a9e75b83ca26e50"},"schema_version":"1.0","source":{"id":"2002.03638","kind":"arxiv","version":4}},"canonical_sha256":"543835ea00df07fcfb70121a84f6e0fa0c560b838a61a4cf4b8390da34ffda7d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"543835ea00df07fcfb70121a84f6e0fa0c560b838a61a4cf4b8390da34ffda7d","first_computed_at":"2026-07-05T01:36:28.480061Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:36:28.480061Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"zOPV4sN2S+bhLxz60hmdHlGU9W9SVnKR43W6f2UetQYgqXmAvWq4fGksJnugjZBTvL5X9sSof+a/idUy7BLBAg==","signature_status":"signed_v1","signed_at":"2026-07-05T01:36:28.480554Z","signed_message":"canonical_sha256_bytes"},"source_id":"2002.03638","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ff62d86c5ee57ed3eff96cc77fdbf69d159e7c341ff27a1f3ce42fe3d04828c9","sha256:67ea80d7879ee06386a288527fa7e2ce18f0b772b22985ad240d5bf820c80927"],"state_sha256":"12d5b91a2760b63b07961c07932afa3df17f474cfd5658fae61620fd462c71ca"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"IArDsi/1bBSej5KGld3ORinVXvBJa6TRrPxbhe2WEeLjMjjeDtbwwQl1CyeocgHpNNj+2Yiz6F8ClGIBC6tmDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-15T10:52:20.755977Z","bundle_sha256":"f053033aca479dc21abe3ba1cefe4e1e90e8b7b862a66178baf00138198a85dc"}}