{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2003:HFQ7EBPYJX72TFAZXBHYUXHGO7","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":"2bceb9ce952efe58b941111a44b195031ca5c4b2c4a3f3f508bb690628dabef0","cross_cats_sorted":["astro-ph","hep-th"],"license":"","primary_cat":"gr-qc","submitted_at":"2003-05-13T18:18:34Z","title_canon_sha256":"add0c8e4779346c098458c64d3ff2bd140a1300c811d756ffdb5ea2b363118f3"},"schema_version":"1.0","source":{"id":"gr-qc/0305049","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"gr-qc/0305049","created_at":"2026-07-04T16:40:12Z"},{"alias_kind":"arxiv_version","alias_value":"gr-qc/0305049v1","created_at":"2026-07-04T16:40:12Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.gr-qc/0305049","created_at":"2026-07-04T16:40:12Z"},{"alias_kind":"pith_short_12","alias_value":"HFQ7EBPYJX72","created_at":"2026-07-04T16:40:12Z"},{"alias_kind":"pith_short_16","alias_value":"HFQ7EBPYJX72TFAZ","created_at":"2026-07-04T16:40:12Z"},{"alias_kind":"pith_short_8","alias_value":"HFQ7EBPY","created_at":"2026-07-04T16:40:12Z"}],"graph_snapshots":[{"event_id":"sha256:48cdc6c1756a2ee968304da7c166f6e9b0a6eae89dbc05f1470d32450f578087","target":"graph","created_at":"2026-07-04T16:40:12Z","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/gr-qc/0305049/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In conventional Maxwell--Lorentz electrodynamics, the propagation of light is influenced by the metric, not, however, by the possible presence of a torsion T. Still the light can feel torsion if the latter is coupled nonminimally to the electromagnetic field F by means of a supplementary Lagrangian of the type l^2 T^2 F^2 (l = coupling constant). Recently Preuss suggested a specific nonminimal term of this nature. We evaluate the spacetime relation of Preuss in the background of a general O(3)-symmetric torsion field and prove by specifying the optical metric of spacetime that this can yield b","authors_text":"Friedrich W. Hehl, Guillermo F. Rubilar, Yuri N. Obukhov","cross_cats":["astro-ph","hep-th"],"headline":"","license":"","primary_cat":"gr-qc","submitted_at":"2003-05-13T18:18:34Z","title":"Torsion nonminimally coupled to the electromagnetic field and birefringence"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"gr-qc/0305049","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:afd6d4869a1f438943fb5379a090b8c1c0e60c8061e4cbe36ede4df6c9d5e903","target":"record","created_at":"2026-07-04T16:40:12Z","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":"2bceb9ce952efe58b941111a44b195031ca5c4b2c4a3f3f508bb690628dabef0","cross_cats_sorted":["astro-ph","hep-th"],"license":"","primary_cat":"gr-qc","submitted_at":"2003-05-13T18:18:34Z","title_canon_sha256":"add0c8e4779346c098458c64d3ff2bd140a1300c811d756ffdb5ea2b363118f3"},"schema_version":"1.0","source":{"id":"gr-qc/0305049","kind":"arxiv","version":1}},"canonical_sha256":"3961f205f84dffa99419b84f8a5ce677cf17e4e2447771732b1d9b607026c6e5","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"3961f205f84dffa99419b84f8a5ce677cf17e4e2447771732b1d9b607026c6e5","first_computed_at":"2026-07-04T16:40:12.639084Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T16:40:12.639084Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"szGm2r1rrBD3JlqnAZzcmdbSHwLm64CKKz4r9BdxN3Rpin3NFa0zuRMnCVuLInwYd/7XsitXRycJKAg0iQlyBw==","signature_status":"signed_v1","signed_at":"2026-07-04T16:40:12.639503Z","signed_message":"canonical_sha256_bytes"},"source_id":"gr-qc/0305049","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:afd6d4869a1f438943fb5379a090b8c1c0e60c8061e4cbe36ede4df6c9d5e903","sha256:48cdc6c1756a2ee968304da7c166f6e9b0a6eae89dbc05f1470d32450f578087"],"state_sha256":"acf435eb2e172a9fa0eddbd37e4a9ba2c3cf73d0d9e62e39550490b41836bd2f"}