{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:W2WAJM2R53DMWBUBG5KPTJNE5C","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":"277f758d4e49052108cd43bf6e8af7ece95b95ef3467d9008b23d066a222871f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-01-29T21:49:28Z","title_canon_sha256":"3f46c2e0fca339c0a79baf08baa918d268d6fdd34a83455e88948d5a4e03885b"},"schema_version":"1.0","source":{"id":"1801.09776","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.09776","created_at":"2026-05-18T00:24:53Z"},{"alias_kind":"arxiv_version","alias_value":"1801.09776v1","created_at":"2026-05-18T00:24:53Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.09776","created_at":"2026-05-18T00:24:53Z"},{"alias_kind":"pith_short_12","alias_value":"W2WAJM2R53DM","created_at":"2026-05-18T12:32:59Z"},{"alias_kind":"pith_short_16","alias_value":"W2WAJM2R53DMWBUB","created_at":"2026-05-18T12:32:59Z"},{"alias_kind":"pith_short_8","alias_value":"W2WAJM2R","created_at":"2026-05-18T12:32:59Z"}],"graph_snapshots":[{"event_id":"sha256:4cf004a44842e2f0a779565186d860acabd7c325a4f2092686fe566374f3dd50","target":"graph","created_at":"2026-05-18T00:24:53Z","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":"In this work, we use two decadal sunspot number series reconstructed from cosmogenic radionuclide data (14C in tree trunks, SN-14C and 10Be in polar ice, SN-10Be) and the Extreme Value Theory to study variability of solar activity during the last 9 millennia. The peaks-over-threshold technique was used to compute, in particular, the shape parameter of the generalized Pareto distribution for different thresholds. Its negative value implies an upper bound of the extreme SN-10Be and SN-14C time series. The return level for 1000 and 10000 years were estimated leading to values lower than the maxim","authors_text":"F.J. Acero, I.G. Usoskin, J.A. Garc\\'ia, J.M. Vaquero, M.C. Gallego","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-01-29T21:49:28Z","title":"Extreme value theory applied to the millennial sunspot number series"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.09776","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:dec62f199c8064f2ba3aec57db94c6db16c74b67dfd201b38906a093e46e6d75","target":"record","created_at":"2026-05-18T00:24:53Z","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":"277f758d4e49052108cd43bf6e8af7ece95b95ef3467d9008b23d066a222871f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.SR","submitted_at":"2018-01-29T21:49:28Z","title_canon_sha256":"3f46c2e0fca339c0a79baf08baa918d268d6fdd34a83455e88948d5a4e03885b"},"schema_version":"1.0","source":{"id":"1801.09776","kind":"arxiv","version":1}},"canonical_sha256":"b6ac04b351eec6cb06813754f9a5a4e8b6c2ddea1f499ac8386eee76962d855f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b6ac04b351eec6cb06813754f9a5a4e8b6c2ddea1f499ac8386eee76962d855f","first_computed_at":"2026-05-18T00:24:53.822165Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:24:53.822165Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"HYP7xpg2mMthSZsE3+eqgFNoAYwP9R8fhZ4N1DKBekR9QCkgNL4YZN50f6RUxSYZHivCQ3g40mKQRZYq3Fq7BA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:24:53.822818Z","signed_message":"canonical_sha256_bytes"},"source_id":"1801.09776","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:dec62f199c8064f2ba3aec57db94c6db16c74b67dfd201b38906a093e46e6d75","sha256:4cf004a44842e2f0a779565186d860acabd7c325a4f2092686fe566374f3dd50"],"state_sha256":"9a6630541400fd1cac8cb7dce4d9e7f7668a9005a0f2490127ba9c3f1b8b7450"}