{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:4UHBCRKR2PSAAZSNSXGAIYH3VA","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":"0ca068325fff88d983cdca71a7d69eb8cad8dd342f63c0fccd1d5a34a9bb6bf2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2016-09-19T13:30:14Z","title_canon_sha256":"cbd35f4f40949b81164a179280c053466e066e84d242be44bc2b195bc4bc84bf"},"schema_version":"1.0","source":{"id":"1609.05718","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1609.05718","created_at":"2026-05-18T00:02:50Z"},{"alias_kind":"arxiv_version","alias_value":"1609.05718v2","created_at":"2026-05-18T00:02:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1609.05718","created_at":"2026-05-18T00:02:50Z"},{"alias_kind":"pith_short_12","alias_value":"4UHBCRKR2PSA","created_at":"2026-05-18T12:29:58Z"},{"alias_kind":"pith_short_16","alias_value":"4UHBCRKR2PSAAZSN","created_at":"2026-05-18T12:29:58Z"},{"alias_kind":"pith_short_8","alias_value":"4UHBCRKR","created_at":"2026-05-18T12:29:58Z"}],"graph_snapshots":[{"event_id":"sha256:19b6403336a8483ac4e5e72a0e045f89acf4ed0fa02c7a6a1982a1acea147610","target":"graph","created_at":"2026-05-18T00:02:50Z","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":"We describe an optical frequency stabilization scheme of a microwave oscillator that is used for the interrogation of primary caesium fountain clocks. Because of its superior phase noise properties, this scheme, which is based on an ultrastable laser and a femtosecond laser frequency comb, overcomes the frequency instability limitations of fountain clocks given by the previously utilized quartz-oscillator-based frequency synthesis. The presented scheme combines the transfer of the short-term frequency instability of an optical cavity and the long-term frequency instability of a hydrogen maser ","authors_text":"Burghard Lipphardt, Stefan Weyers, Vladislav Gerginov","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2016-09-19T13:30:14Z","title":"Optical Stabilization of a Microwave Oscillator for Fountain Clock Interrogation"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.05718","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:c44e9f1ee6af75c694acb915dd29cd22c043e82679ef7ff9e31d778b442e68a5","target":"record","created_at":"2026-05-18T00:02:50Z","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":"0ca068325fff88d983cdca71a7d69eb8cad8dd342f63c0fccd1d5a34a9bb6bf2","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2016-09-19T13:30:14Z","title_canon_sha256":"cbd35f4f40949b81164a179280c053466e066e84d242be44bc2b195bc4bc84bf"},"schema_version":"1.0","source":{"id":"1609.05718","kind":"arxiv","version":2}},"canonical_sha256":"e50e114551d3e400664d95cc0460fba835fc300f83e3199cb69ebaaea55180c8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e50e114551d3e400664d95cc0460fba835fc300f83e3199cb69ebaaea55180c8","first_computed_at":"2026-05-18T00:02:50.101081Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:02:50.101081Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"u8k/kjtO/3adpNbF/KYZWuE5hLd5pZBq53CEDcdlbU0QycGDSDOWyjKc12jOLNmO+VPw7RRrRRZhVYhYGDC0Dg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:02:50.101505Z","signed_message":"canonical_sha256_bytes"},"source_id":"1609.05718","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c44e9f1ee6af75c694acb915dd29cd22c043e82679ef7ff9e31d778b442e68a5","sha256:19b6403336a8483ac4e5e72a0e045f89acf4ed0fa02c7a6a1982a1acea147610"],"state_sha256":"f74805b50e6b10970d435e4343fcde78e2cb5ea3c0497930684e1b5052c7c8f6"}