{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:EYGFAWTLZJWNUM5EQL6VNKPQTY","short_pith_number":"pith:EYGFAWTL","canonical_record":{"source":{"id":"2605.05489","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2026-05-06T22:24:31Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"53cd8ac451aaee980d8496f04d0ec40f4c11296f919fa4bc9905da4549cad6be","abstract_canon_sha256":"2eb82274c3ecf9152321ff0dd8dd26dba5fa1411755c90e9f9a5f326db76cee4"},"schema_version":"1.0"},"canonical_sha256":"260c505a6bca6cda33a482fd56a9f09e29fde115653399af517c2787b2656d85","source":{"kind":"arxiv","id":"2605.05489","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2605.05489","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"arxiv_version","alias_value":"2605.05489v2","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2605.05489","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_12","alias_value":"EYGFAWTLZJWN","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_16","alias_value":"EYGFAWTLZJWNUM5E","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_8","alias_value":"EYGFAWTL","created_at":"2026-06-23T02:13:24Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:EYGFAWTLZJWNUM5EQL6VNKPQTY","target":"record","payload":{"canonical_record":{"source":{"id":"2605.05489","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2026-05-06T22:24:31Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"53cd8ac451aaee980d8496f04d0ec40f4c11296f919fa4bc9905da4549cad6be","abstract_canon_sha256":"2eb82274c3ecf9152321ff0dd8dd26dba5fa1411755c90e9f9a5f326db76cee4"},"schema_version":"1.0"},"canonical_sha256":"260c505a6bca6cda33a482fd56a9f09e29fde115653399af517c2787b2656d85","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-23T02:13:24.737068Z","signature_b64":"9fgIE3gE2hd1QmNG4ulmI8zzdQ/rPJrg/Nv8MqL3KGPlttORuEdaq7GggIJwUXvcUGcPWm4/Fetmq1ndwRsyCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"260c505a6bca6cda33a482fd56a9f09e29fde115653399af517c2787b2656d85","last_reissued_at":"2026-06-23T02:13:24.736672Z","signature_status":"signed_v1","first_computed_at":"2026-06-23T02:13:24.736672Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2605.05489","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":"2026-06-23T02:13:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"K0MiBp3J7FKnFEXHU1J1jOCHAU8qqK6VlTHB3veSs+86KggA6fW6YMh0Pvb4n3jigx02UsIb5hBblO9DbxtTDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T19:43:38.510496Z"},"content_sha256":"63644a64089aa67a9d1582ae218c29148ff12d379d4e2b52cd23a5c6045a30a1","schema_version":"1.0","event_id":"sha256:63644a64089aa67a9d1582ae218c29148ff12d379d4e2b52cd23a5c6045a30a1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:EYGFAWTLZJWNUM5EQL6VNKPQTY","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Systematic Spectral Distortion from Digital Whitening in Radio Telescopes and Implications for 21 cm Cosmology","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology.","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.IM","authors_text":"Daniel C. Jacobs, Gregg Hallinan, Larry R. D'Addario, Ruby Byrne","submitted_at":"2026-05-06T22:24:31Z","abstract_excerpt":"We identify a systematic distortion of the gain-vs.-frequency function of radio telescopes caused by digital flattening (\"whitening\") of the signal's spectrum followed by re-quantization, a common pair of processes in the signal processing of modern telescopes. Wide-bandwidth telescopes often have a large variation of signal power over frequency. Flattening of the spectrum allows samples of the channelized signal to be represented in a small number of bits, allowing efficient downstream processing. However, we show that this produces subtle systematic error in the measured spectra. We explore "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Although the effect can be small so that it has heretofore been unrecognized, we demonstrate that it produces distortion of the spectrum at a level that is problematic for some science, in particular 21 cm cosmology.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the observed distortion in OVRO-LWA data and the semi-analytic simulations arise specifically and solely from the whitening-plus-re-quantization sequence rather than from other unmodeled instrumental or environmental effects.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Digital spectrum whitening followed by re-quantization introduces a previously unrecognized systematic distortion in the gain-versus-frequency response of radio telescopes, reaching levels problematic for 21 cm cosmology.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"5d925ba4cb6febc7ca0426de28208d30c56750e69b844fce4cdbba2d262b11b4"},"source":{"id":"2605.05489","kind":"arxiv","version":2},"verdict":{"id":"67958db1-b0ea-40df-939c-d9de5ce64123","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-08T15:35:47.610647Z","strongest_claim":"Although the effect can be small so that it has heretofore been unrecognized, we demonstrate that it produces distortion of the spectrum at a level that is problematic for some science, in particular 21 cm cosmology.","one_line_summary":"Digital spectrum whitening followed by re-quantization introduces a previously unrecognized systematic distortion in the gain-versus-frequency response of radio telescopes, reaching levels problematic for 21 cm cosmology.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the observed distortion in OVRO-LWA data and the semi-analytic simulations arise specifically and solely from the whitening-plus-re-quantization sequence rather than from other unmodeled instrumental or environmental effects.","pith_extraction_headline":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.05489/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T09:40:48.948838Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_title_agreement","ran_at":"2026-05-19T20:31:19.583466Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T13:30:46.447379Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"1aa97978184b3ff9de4bcad55657e1506f3039495e26b9fa95ca468fc29f36cc"},"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":"67958db1-b0ea-40df-939c-d9de5ce64123"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-23T02:13:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LcZdKMv/uaDUzRhKt9axPmOHYbNrWg/rG8bDp+PCmoFKylW5OZvxYwGxoRbZ2RJycSfi1b7MsUiQ2ogg8ZPIDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T19:43:38.510977Z"},"content_sha256":"f61478cba978f89f69ad8414f0982af9f0b897ff05ddd811637c9a742a2b2d12","schema_version":"1.0","event_id":"sha256:f61478cba978f89f69ad8414f0982af9f0b897ff05ddd811637c9a742a2b2d12"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/bundle.json","state_url":"https://pith.science/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/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":"2026-06-27T19:43:38Z","links":{"resolver":"https://pith.science/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY","bundle":"https://pith.science/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/bundle.json","state":"https://pith.science/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EYGFAWTLZJWNUM5EQL6VNKPQTY/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:EYGFAWTLZJWNUM5EQL6VNKPQTY","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":"2eb82274c3ecf9152321ff0dd8dd26dba5fa1411755c90e9f9a5f326db76cee4","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2026-05-06T22:24:31Z","title_canon_sha256":"53cd8ac451aaee980d8496f04d0ec40f4c11296f919fa4bc9905da4549cad6be"},"schema_version":"1.0","source":{"id":"2605.05489","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2605.05489","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"arxiv_version","alias_value":"2605.05489v2","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2605.05489","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_12","alias_value":"EYGFAWTLZJWN","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_16","alias_value":"EYGFAWTLZJWNUM5E","created_at":"2026-06-23T02:13:24Z"},{"alias_kind":"pith_short_8","alias_value":"EYGFAWTL","created_at":"2026-06-23T02:13:24Z"}],"graph_snapshots":[{"event_id":"sha256:f61478cba978f89f69ad8414f0982af9f0b897ff05ddd811637c9a742a2b2d12","target":"graph","created_at":"2026-06-23T02:13:24Z","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":4,"items":[{"attestation":"unclaimed","claim_id":"C1","kind":"strongest_claim","source":"verdict.strongest_claim","status":"machine_extracted","text":"Although the effect can be small so that it has heretofore been unrecognized, we demonstrate that it produces distortion of the spectrum at a level that is problematic for some science, in particular 21 cm cosmology."},{"attestation":"unclaimed","claim_id":"C2","kind":"weakest_assumption","source":"verdict.weakest_assumption","status":"machine_extracted","text":"That the observed distortion in OVRO-LWA data and the semi-analytic simulations arise specifically and solely from the whitening-plus-re-quantization sequence rather than from other unmodeled instrumental or environmental effects."},{"attestation":"unclaimed","claim_id":"C3","kind":"one_line_summary","source":"verdict.one_line_summary","status":"machine_extracted","text":"Digital spectrum whitening followed by re-quantization introduces a previously unrecognized systematic distortion in the gain-versus-frequency response of radio telescopes, reaching levels problematic for 21 cm cosmology."},{"attestation":"unclaimed","claim_id":"C4","kind":"headline","source":"verdict.pith_extraction.headline","status":"machine_extracted","text":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology."}],"snapshot_sha256":"5d925ba4cb6febc7ca0426de28208d30c56750e69b844fce4cdbba2d262b11b4"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[{"findings_count":0,"name":"ai_meta_artifact","ran_at":"2026-05-20T09:40:48.948838Z","status":"completed","version":"1.0.0"},{"findings_count":0,"name":"doi_title_agreement","ran_at":"2026-05-19T20:31:19.583466Z","status":"completed","version":"1.0.0"},{"findings_count":0,"name":"doi_compliance","ran_at":"2026-05-19T13:30:46.447379Z","status":"completed","version":"1.0.0"}],"endpoint":"/pith/2605.05489/integrity.json","findings":[],"snapshot_sha256":"1aa97978184b3ff9de4bcad55657e1506f3039495e26b9fa95ca468fc29f36cc","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We identify a systematic distortion of the gain-vs.-frequency function of radio telescopes caused by digital flattening (\"whitening\") of the signal's spectrum followed by re-quantization, a common pair of processes in the signal processing of modern telescopes. Wide-bandwidth telescopes often have a large variation of signal power over frequency. Flattening of the spectrum allows samples of the channelized signal to be represented in a small number of bits, allowing efficient downstream processing. However, we show that this produces subtle systematic error in the measured spectra. We explore ","authors_text":"Daniel C. Jacobs, Gregg Hallinan, Larry R. D'Addario, Ruby Byrne","cross_cats":["astro-ph.CO"],"headline":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology.","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2026-05-06T22:24:31Z","title":"Systematic Spectral Distortion from Digital Whitening in Radio Telescopes and Implications for 21 cm Cosmology"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2605.05489","kind":"arxiv","version":2},"verdict":{"created_at":"2026-05-08T15:35:47.610647Z","id":"67958db1-b0ea-40df-939c-d9de5ce64123","model_set":{"reader":"grok-4.3"},"one_line_summary":"Digital spectrum whitening followed by re-quantization introduces a previously unrecognized systematic distortion in the gain-versus-frequency response of radio telescopes, reaching levels problematic for 21 cm cosmology.","pipeline_version":"pith-pipeline@v0.9.0","pith_extraction_headline":"Digital whitening of radio signals followed by re-quantization introduces systematic spectral distortions at levels problematic for 21 cm cosmology.","strongest_claim":"Although the effect can be small so that it has heretofore been unrecognized, we demonstrate that it produces distortion of the spectrum at a level that is problematic for some science, in particular 21 cm cosmology.","weakest_assumption":"That the observed distortion in OVRO-LWA data and the semi-analytic simulations arise specifically and solely from the whitening-plus-re-quantization sequence rather than from other unmodeled instrumental or environmental effects."}},"verdict_id":"67958db1-b0ea-40df-939c-d9de5ce64123"}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:63644a64089aa67a9d1582ae218c29148ff12d379d4e2b52cd23a5c6045a30a1","target":"record","created_at":"2026-06-23T02:13:24Z","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":"2eb82274c3ecf9152321ff0dd8dd26dba5fa1411755c90e9f9a5f326db76cee4","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2026-05-06T22:24:31Z","title_canon_sha256":"53cd8ac451aaee980d8496f04d0ec40f4c11296f919fa4bc9905da4549cad6be"},"schema_version":"1.0","source":{"id":"2605.05489","kind":"arxiv","version":2}},"canonical_sha256":"260c505a6bca6cda33a482fd56a9f09e29fde115653399af517c2787b2656d85","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"260c505a6bca6cda33a482fd56a9f09e29fde115653399af517c2787b2656d85","first_computed_at":"2026-06-23T02:13:24.736672Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-23T02:13:24.736672Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"9fgIE3gE2hd1QmNG4ulmI8zzdQ/rPJrg/Nv8MqL3KGPlttORuEdaq7GggIJwUXvcUGcPWm4/Fetmq1ndwRsyCw==","signature_status":"signed_v1","signed_at":"2026-06-23T02:13:24.737068Z","signed_message":"canonical_sha256_bytes"},"source_id":"2605.05489","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:63644a64089aa67a9d1582ae218c29148ff12d379d4e2b52cd23a5c6045a30a1","sha256:f61478cba978f89f69ad8414f0982af9f0b897ff05ddd811637c9a742a2b2d12"],"state_sha256":"408831eadca3f813b9a9167923b1b0adf9a72f7bfc3f1542ae7c94c3fabab32f"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Z1NHwpBL3Pu60nWogOe41T10TstzOjEdIXl2rgnv0NFAETaLrxHC3TKgXx8hmhzwYQrt8GHrDyHCku0dY3MnCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-27T19:43:38.513207Z","bundle_sha256":"60460c8e6f8d59e58d59b1a2201b3184a4f342ddf258628f66e73d11274e4db0"}}