{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:WSIAOIP77YMU7W77UG7KY3DSFM","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":"90cf725ad38aa96609f4837406674b37d345eb9e3887e9ae0b2cd8233b726205","cross_cats_sorted":["hep-ex","physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2018-05-08T08:19:07Z","title_canon_sha256":"b77050ee31010e2acac09c45438c55b2647237f5ca1c8ce199d2933b44f3bd26"},"schema_version":"1.0","source":{"id":"1805.03198","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1805.03198","created_at":"2026-05-18T00:08:07Z"},{"alias_kind":"arxiv_version","alias_value":"1805.03198v1","created_at":"2026-05-18T00:08:07Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1805.03198","created_at":"2026-05-18T00:08:07Z"},{"alias_kind":"pith_short_12","alias_value":"WSIAOIP77YMU","created_at":"2026-05-18T12:33:01Z"},{"alias_kind":"pith_short_16","alias_value":"WSIAOIP77YMU7W77","created_at":"2026-05-18T12:33:01Z"},{"alias_kind":"pith_short_8","alias_value":"WSIAOIP7","created_at":"2026-05-18T12:33:01Z"}],"graph_snapshots":[{"event_id":"sha256:8cca22728ebc09bdc5e6e6121abb0f69f851cbf1104a538672549211aa6b9580","target":"graph","created_at":"2026-05-18T00:08:07Z","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":"Although experimental efforts have been active for about 30 years now, a direct laboratory observation of vacuum magnetic birefringence, an effect due to vacuum fluctuations, still needs confirmation. Indeed, the predicted birefringence of vacuum is $\\Delta n = 4.0\\times 10^{-24}$ @ 1~T. One of the key ingredients when designing a polarimeter capable of detecting such a small birefringence is a long optical path length within the magnetic field and a time dependent effect. To lengthen the optical path within the magnetic field a Fabry-Perot optical cavity is generally used with a finesse rangi","authors_text":"A. Ejlli, E. Milotti, F. Della Valle, G. Ruoso, G. Zavattini, R. Pengo, U. Gastaldi, W.-T. Ni","cross_cats":["hep-ex","physics.optics"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2018-05-08T08:19:07Z","title":"Intrinsic mirror noise in Fabry-Perot based polarimeters: the case for the measurement of vacuum magnetic birefringence"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1805.03198","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":"sha256:3499bae9ae50d0620d457b17900f5f7c5129891f9f77c2b7a39278cd6eac10ee","target":"record","created_at":"2026-05-18T00:08:07Z","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":"90cf725ad38aa96609f4837406674b37d345eb9e3887e9ae0b2cd8233b726205","cross_cats_sorted":["hep-ex","physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2018-05-08T08:19:07Z","title_canon_sha256":"b77050ee31010e2acac09c45438c55b2647237f5ca1c8ce199d2933b44f3bd26"},"schema_version":"1.0","source":{"id":"1805.03198","kind":"arxiv","version":1}},"canonical_sha256":"b4900721fffe194fdbffa1beac6c722b3b273257d5b94c1b045ae4dbcd2a2266","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b4900721fffe194fdbffa1beac6c722b3b273257d5b94c1b045ae4dbcd2a2266","first_computed_at":"2026-05-18T00:08:07.145898Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:08:07.145898Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"1FMBU+MtmObJjbtA/KwDWx2o0kCTu2BejK5c55QGsitciBDximQ7q3v2ZjLOP+LXfHcPPMH/twfoxiCeKNpMBw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:08:07.146489Z","signed_message":"canonical_sha256_bytes"},"source_id":"1805.03198","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:3499bae9ae50d0620d457b17900f5f7c5129891f9f77c2b7a39278cd6eac10ee","sha256:8cca22728ebc09bdc5e6e6121abb0f69f851cbf1104a538672549211aa6b9580"],"state_sha256":"7259b60fc8cfe68be1e9e932f8bc0e5703da6043c39fb6368c602db884206034"}