{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2008:R76MOBL366UGCH46TJOSQAFFIR","short_pith_number":"pith:R76MOBL3","canonical_record":{"source":{"id":"0809.1763","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-09-10T11:17:36Z","cross_cats_sorted":["gr-qc","hep-ph"],"title_canon_sha256":"8ee17844577c710e94afeff64ce7706e690103365c24acda1a0f3a63010ab619","abstract_canon_sha256":"70776c63029f05b8b24f70d01a57cb3854f7cb544dfae6c73f305b8f07c4affc"},"schema_version":"1.0"},"canonical_sha256":"8ffcc7057bf7a8611f9e9a5d2800a544550f50c42e051bec502c2bbe5e89d118","source":{"kind":"arxiv","id":"0809.1763","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0809.1763","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"arxiv_version","alias_value":"0809.1763v2","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0809.1763","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_12","alias_value":"R76MOBL366UG","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_16","alias_value":"R76MOBL366UGCH46","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_8","alias_value":"R76MOBL3","created_at":"2026-07-04T15:39:22Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2008:R76MOBL366UGCH46TJOSQAFFIR","target":"record","payload":{"canonical_record":{"source":{"id":"0809.1763","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-09-10T11:17:36Z","cross_cats_sorted":["gr-qc","hep-ph"],"title_canon_sha256":"8ee17844577c710e94afeff64ce7706e690103365c24acda1a0f3a63010ab619","abstract_canon_sha256":"70776c63029f05b8b24f70d01a57cb3854f7cb544dfae6c73f305b8f07c4affc"},"schema_version":"1.0"},"canonical_sha256":"8ffcc7057bf7a8611f9e9a5d2800a544550f50c42e051bec502c2bbe5e89d118","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T15:39:22.878209Z","signature_b64":"/rt75ysIrwPJT554iMmGoD0E0mZGNXaha5MZWrqNtnrFqken/2oIrVV7nzSClHSnBxOlPgNLiWVw3yl6WYqzCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8ffcc7057bf7a8611f9e9a5d2800a544550f50c42e051bec502c2bbe5e89d118","last_reissued_at":"2026-07-04T15:39:22.877814Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T15:39:22.877814Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0809.1763","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T15:39:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1aAlyAL1gWgo11NJgVap/zkppRIh4P2td75Qwd4tsTvQJ5dNtUuhi5GaP1lN4+761aXt6X67OKOJBJx6jlfyAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T20:53:11.343431Z"},"content_sha256":"da14e392784ce6c5139137f8fe4b0a04a68f30c1ec7d7e0bbe30d7fdd1be1c57","schema_version":"1.0","event_id":"sha256:da14e392784ce6c5139137f8fe4b0a04a68f30c1ec7d7e0bbe30d7fdd1be1c57"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2008:R76MOBL366UGCH46TJOSQAFFIR","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Detecting Chameleons: The Astronomical Polarization Produced by Chameleon-like Scalar Fields","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["gr-qc","hep-ph"],"primary_cat":"astro-ph","authors_text":"Anne-Christine Davis, Clare Burrage, Douglas J. Shaw","submitted_at":"2008-09-10T11:17:36Z","abstract_excerpt":"We show that a coupling between chameleon-like scalar fields and photons induces linear and circular polarization in the light from astrophysical sources. In this context chameleon-like scalar fields includes those of the Olive-Pospelov (OP) model describing a varying fine structure constant. We determine the form of this polarization numerically and give analytic expressions in two useful limits. By comparing the predicted signal with current observations we are able to improve the constraints on the chameleon-photon coupling and the coupling in the OP model by over two orders of magnitude. I"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0809.1763","kind":"arxiv","version":2},"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/0809.1763/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":"2026-07-04T15:39:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VL9ZgU57sGe1bCTNKrH1VQNY+/0d6KMh6xCL9/ohdaaP8QGofbf4TnAXv2L8dTbf4gBThpXBAkjNu7H4pljDDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T20:53:11.343925Z"},"content_sha256":"a965485fa0c401cfdcb1be280ab4d25184818f0d614d1ae92626dc170bc996d8","schema_version":"1.0","event_id":"sha256:a965485fa0c401cfdcb1be280ab4d25184818f0d614d1ae92626dc170bc996d8"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/R76MOBL366UGCH46TJOSQAFFIR/bundle.json","state_url":"https://pith.science/pith/R76MOBL366UGCH46TJOSQAFFIR/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/R76MOBL366UGCH46TJOSQAFFIR/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":"2026-08-04T20:53:11Z","links":{"resolver":"https://pith.science/pith/R76MOBL366UGCH46TJOSQAFFIR","bundle":"https://pith.science/pith/R76MOBL366UGCH46TJOSQAFFIR/bundle.json","state":"https://pith.science/pith/R76MOBL366UGCH46TJOSQAFFIR/state.json","well_known_bundle":"https://pith.science/.well-known/pith/R76MOBL366UGCH46TJOSQAFFIR/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2008:R76MOBL366UGCH46TJOSQAFFIR","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":"70776c63029f05b8b24f70d01a57cb3854f7cb544dfae6c73f305b8f07c4affc","cross_cats_sorted":["gr-qc","hep-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-09-10T11:17:36Z","title_canon_sha256":"8ee17844577c710e94afeff64ce7706e690103365c24acda1a0f3a63010ab619"},"schema_version":"1.0","source":{"id":"0809.1763","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0809.1763","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"arxiv_version","alias_value":"0809.1763v2","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0809.1763","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_12","alias_value":"R76MOBL366UG","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_16","alias_value":"R76MOBL366UGCH46","created_at":"2026-07-04T15:39:22Z"},{"alias_kind":"pith_short_8","alias_value":"R76MOBL3","created_at":"2026-07-04T15:39:22Z"}],"graph_snapshots":[{"event_id":"sha256:a965485fa0c401cfdcb1be280ab4d25184818f0d614d1ae92626dc170bc996d8","target":"graph","created_at":"2026-07-04T15:39:22Z","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/0809.1763/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We show that a coupling between chameleon-like scalar fields and photons induces linear and circular polarization in the light from astrophysical sources. In this context chameleon-like scalar fields includes those of the Olive-Pospelov (OP) model describing a varying fine structure constant. We determine the form of this polarization numerically and give analytic expressions in two useful limits. By comparing the predicted signal with current observations we are able to improve the constraints on the chameleon-photon coupling and the coupling in the OP model by over two orders of magnitude. I","authors_text":"Anne-Christine Davis, Clare Burrage, Douglas J. Shaw","cross_cats":["gr-qc","hep-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-09-10T11:17:36Z","title":"Detecting Chameleons: The Astronomical Polarization Produced by Chameleon-like Scalar Fields"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0809.1763","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:da14e392784ce6c5139137f8fe4b0a04a68f30c1ec7d7e0bbe30d7fdd1be1c57","target":"record","created_at":"2026-07-04T15:39:22Z","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":"70776c63029f05b8b24f70d01a57cb3854f7cb544dfae6c73f305b8f07c4affc","cross_cats_sorted":["gr-qc","hep-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-09-10T11:17:36Z","title_canon_sha256":"8ee17844577c710e94afeff64ce7706e690103365c24acda1a0f3a63010ab619"},"schema_version":"1.0","source":{"id":"0809.1763","kind":"arxiv","version":2}},"canonical_sha256":"8ffcc7057bf7a8611f9e9a5d2800a544550f50c42e051bec502c2bbe5e89d118","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8ffcc7057bf7a8611f9e9a5d2800a544550f50c42e051bec502c2bbe5e89d118","first_computed_at":"2026-07-04T15:39:22.877814Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T15:39:22.877814Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"/rt75ysIrwPJT554iMmGoD0E0mZGNXaha5MZWrqNtnrFqken/2oIrVV7nzSClHSnBxOlPgNLiWVw3yl6WYqzCg==","signature_status":"signed_v1","signed_at":"2026-07-04T15:39:22.878209Z","signed_message":"canonical_sha256_bytes"},"source_id":"0809.1763","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:da14e392784ce6c5139137f8fe4b0a04a68f30c1ec7d7e0bbe30d7fdd1be1c57","sha256:a965485fa0c401cfdcb1be280ab4d25184818f0d614d1ae92626dc170bc996d8"],"state_sha256":"66129a7fa4d4e8ce33be64b886d61571d82fe601c29e18ede0bee8c364582fa1"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Jl+PPL/+IR2iF1+iTJCdsBI4RxxMvJUoie/VsNf/x4oovWdNrDGW7U4LCIa1MqDPFZ9gsZA8yCWY3hOwGUAfAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-04T20:53:11.347074Z","bundle_sha256":"4b32ca83931123118f2ddef001b3e0d1d8e027806e2b6147bfff9ec8ab8c2b8b"}}