{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2010:CHQJNUBHOPSI2INSCGSGEY3QLE","short_pith_number":"pith:CHQJNUBH","canonical_record":{"source":{"id":"1004.2540","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-15T03:10:56Z","cross_cats_sorted":["physics.atom-ph"],"title_canon_sha256":"aafd952c77e62cfec248c773613985b56b7cb305e3c23cd693c2c055b07b7516","abstract_canon_sha256":"0925b5c0fc33f54cc95eb3b555ef80e373152644fea79a2615fe02c91eb25b87"},"schema_version":"1.0"},"canonical_sha256":"11e096d02773e48d21b211a46263705908b570150867ea7ab8ca6aad5d189efd","source":{"kind":"arxiv","id":"1004.2540","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1004.2540","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"arxiv_version","alias_value":"1004.2540v2","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1004.2540","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"pith_short_12","alias_value":"CHQJNUBHOPSI","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_16","alias_value":"CHQJNUBHOPSI2INS","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_8","alias_value":"CHQJNUBH","created_at":"2026-05-18T12:26:05Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2010:CHQJNUBHOPSI2INSCGSGEY3QLE","target":"record","payload":{"canonical_record":{"source":{"id":"1004.2540","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-15T03:10:56Z","cross_cats_sorted":["physics.atom-ph"],"title_canon_sha256":"aafd952c77e62cfec248c773613985b56b7cb305e3c23cd693c2c055b07b7516","abstract_canon_sha256":"0925b5c0fc33f54cc95eb3b555ef80e373152644fea79a2615fe02c91eb25b87"},"schema_version":"1.0"},"canonical_sha256":"11e096d02773e48d21b211a46263705908b570150867ea7ab8ca6aad5d189efd","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:33:34.260089Z","signature_b64":"o3mzJEZiKmxqoq4O+9WhWaPunB+f0ITgEHO22+8WwAvnfqp+qEBBdKFhrqFMReBM5/43qw2tt6fTuqoqPZHTDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"11e096d02773e48d21b211a46263705908b570150867ea7ab8ca6aad5d189efd","last_reissued_at":"2026-05-18T02:33:34.259677Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:33:34.259677Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1004.2540","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":"2026-05-18T02:33:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CO9rFDuZhJpTc/bDJY1PGP5dluSe6YrMGEU7EzMljYN2GMaN0vhO4s493K6TIXCnvbS0KCWpj849VvpCnTcSBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T18:58:44.224218Z"},"content_sha256":"fcd91393677101b60209ddded3900e286562dd005bbebdb25af112120afac655","schema_version":"1.0","event_id":"sha256:fcd91393677101b60209ddded3900e286562dd005bbebdb25af112120afac655"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2010:CHQJNUBHOPSI2INSCGSGEY3QLE","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Comment on \"21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant\"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.atom-ph"],"primary_cat":"astro-ph.CO","authors_text":"S.G. Porsev, V.V. Flambaum","submitted_at":"2010-04-15T03:10:56Z","abstract_excerpt":"Khatri and Wandelt reported that change in the value of alpha by 1% changes the mean brightness temperature $T_b$ decrement of the CMB due to 21 cm absorption by 5% over the redshift range z $<$ 50. A drawback of their approach is that the dimensionful parameters are used. Changing of units leads to the change of the magnitude and even sign of the effect. Similar problems may be identified in a large number of other publications which consider limits on the variation of alpha using dimentionful parameters. We propose a method to obtain consistent results and provide an estimate of the effect."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1004.2540","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":""},"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":"2026-05-18T02:33:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"t+eqpq8ed+f0vZ3a0fC7TTyOQe8LA7BqL8RKFuEOMvt+ckn0zWumKY4CcnfNOc+UzTtBXLc9YH0nPPOoPrPvAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T18:58:44.224942Z"},"content_sha256":"8f6df51e3a250d34821c4257093933b4f9e41912c569d0cbace6d5774d96e2c3","schema_version":"1.0","event_id":"sha256:8f6df51e3a250d34821c4257093933b4f9e41912c569d0cbace6d5774d96e2c3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/bundle.json","state_url":"https://pith.science/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/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":"2026-05-25T18:58:44Z","links":{"resolver":"https://pith.science/pith/CHQJNUBHOPSI2INSCGSGEY3QLE","bundle":"https://pith.science/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/bundle.json","state":"https://pith.science/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/state.json","well_known_bundle":"https://pith.science/.well-known/pith/CHQJNUBHOPSI2INSCGSGEY3QLE/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:CHQJNUBHOPSI2INSCGSGEY3QLE","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":"0925b5c0fc33f54cc95eb3b555ef80e373152644fea79a2615fe02c91eb25b87","cross_cats_sorted":["physics.atom-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-15T03:10:56Z","title_canon_sha256":"aafd952c77e62cfec248c773613985b56b7cb305e3c23cd693c2c055b07b7516"},"schema_version":"1.0","source":{"id":"1004.2540","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1004.2540","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"arxiv_version","alias_value":"1004.2540v2","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1004.2540","created_at":"2026-05-18T02:33:34Z"},{"alias_kind":"pith_short_12","alias_value":"CHQJNUBHOPSI","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_16","alias_value":"CHQJNUBHOPSI2INS","created_at":"2026-05-18T12:26:05Z"},{"alias_kind":"pith_short_8","alias_value":"CHQJNUBH","created_at":"2026-05-18T12:26:05Z"}],"graph_snapshots":[{"event_id":"sha256:8f6df51e3a250d34821c4257093933b4f9e41912c569d0cbace6d5774d96e2c3","target":"graph","created_at":"2026-05-18T02:33:34Z","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":"Khatri and Wandelt reported that change in the value of alpha by 1% changes the mean brightness temperature $T_b$ decrement of the CMB due to 21 cm absorption by 5% over the redshift range z $<$ 50. A drawback of their approach is that the dimensionful parameters are used. Changing of units leads to the change of the magnitude and even sign of the effect. Similar problems may be identified in a large number of other publications which consider limits on the variation of alpha using dimentionful parameters. We propose a method to obtain consistent results and provide an estimate of the effect.","authors_text":"S.G. Porsev, V.V. Flambaum","cross_cats":["physics.atom-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-15T03:10:56Z","title":"Comment on \"21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant\""},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1004.2540","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:fcd91393677101b60209ddded3900e286562dd005bbebdb25af112120afac655","target":"record","created_at":"2026-05-18T02:33:34Z","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":"0925b5c0fc33f54cc95eb3b555ef80e373152644fea79a2615fe02c91eb25b87","cross_cats_sorted":["physics.atom-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2010-04-15T03:10:56Z","title_canon_sha256":"aafd952c77e62cfec248c773613985b56b7cb305e3c23cd693c2c055b07b7516"},"schema_version":"1.0","source":{"id":"1004.2540","kind":"arxiv","version":2}},"canonical_sha256":"11e096d02773e48d21b211a46263705908b570150867ea7ab8ca6aad5d189efd","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"11e096d02773e48d21b211a46263705908b570150867ea7ab8ca6aad5d189efd","first_computed_at":"2026-05-18T02:33:34.259677Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:33:34.259677Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"o3mzJEZiKmxqoq4O+9WhWaPunB+f0ITgEHO22+8WwAvnfqp+qEBBdKFhrqFMReBM5/43qw2tt6fTuqoqPZHTDg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:33:34.260089Z","signed_message":"canonical_sha256_bytes"},"source_id":"1004.2540","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:fcd91393677101b60209ddded3900e286562dd005bbebdb25af112120afac655","sha256:8f6df51e3a250d34821c4257093933b4f9e41912c569d0cbace6d5774d96e2c3"],"state_sha256":"a9bd67a3fe2b59f432d8dbedc6f6607c72017595c5e95fe44c053208ab3ede05"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"z9gMO1cYdj655lXuYK8r4LgDmPAdnUCbLSBSkbCzwR2KqevzDYfLq55Vc6e3oBuIU1Ec4nAj4YLej6QYDGszBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T18:58:44.228601Z","bundle_sha256":"ecc27d7c6a353a33ade3cb9a05f185913c2de8fe6620a53097564e1c84b348e0"}}