{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:V5W5NQWDUUDQR7KPAR2KL2G7PX","short_pith_number":"pith:V5W5NQWD","canonical_record":{"source":{"id":"1811.04917","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-11-12T18:56:10Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"a22a6b0c347e917aa7abb83691b79a1df3f715a159df1da269a427ffebdae8e8","abstract_canon_sha256":"bff5f20a7ca919924725d85cfcd37ef898f5a0033eb0e920ad6554d85daa145a"},"schema_version":"1.0"},"canonical_sha256":"af6dd6c2c3a50708fd4f0474a5e8df7ded4a350ec0fd252f92a7daf2f1e85ccc","source":{"kind":"arxiv","id":"1811.04917","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1811.04917","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"arxiv_version","alias_value":"1811.04917v3","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1811.04917","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_12","alias_value":"V5W5NQWDUUDQ","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_16","alias_value":"V5W5NQWDUUDQR7KP","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_8","alias_value":"V5W5NQWD","created_at":"2026-07-05T00:07:34Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:V5W5NQWDUUDQR7KPAR2KL2G7PX","target":"record","payload":{"canonical_record":{"source":{"id":"1811.04917","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-11-12T18:56:10Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"a22a6b0c347e917aa7abb83691b79a1df3f715a159df1da269a427ffebdae8e8","abstract_canon_sha256":"bff5f20a7ca919924725d85cfcd37ef898f5a0033eb0e920ad6554d85daa145a"},"schema_version":"1.0"},"canonical_sha256":"af6dd6c2c3a50708fd4f0474a5e8df7ded4a350ec0fd252f92a7daf2f1e85ccc","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:07:34.749308Z","signature_b64":"7EXLozmnZYnM77Kf4g7WbflrWW1TvVLZoooJjnfj/uyehjCkQ4KdaorU064PU4HMnSrhf6HedFSA6dPK1bf5Aw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"af6dd6c2c3a50708fd4f0474a5e8df7ded4a350ec0fd252f92a7daf2f1e85ccc","last_reissued_at":"2026-07-05T00:07:34.748870Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:07:34.748870Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1811.04917","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T00:07:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"64AG+jn8zFPfoqF78XeR17CSmO1xh05X8GkfXG15yf1jHo1RZsCJ+DG4ud65lXEL8qSOaYXB03ULeE+ne//LBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T21:45:17.620139Z"},"content_sha256":"b315160091e67ad6d7de4027e430355346fcf8cbdaba466d0afecd35df90f90f","schema_version":"1.0","event_id":"sha256:b315160091e67ad6d7de4027e430355346fcf8cbdaba466d0afecd35df90f90f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:V5W5NQWDUUDQR7KPAR2KL2G7PX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Assessment of the Projection-induced Polarimetry Technique for Constraining the Foreground Spectrum in Global 21 cm Cosmology","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.IM","authors_text":"Bang D. Nhan, David D. Bordenave, David Rapetti, Jack O. Burns, Keith Tauscher, Patricia J. Klima, Richard F. Bradley","submitted_at":"2018-11-12T18:56:10Z","abstract_excerpt":"Detecting the cosmological sky-averaged (global) 21 cm signal as a function of observed frequency will provide a powerful tool to study the ionization and thermal history of the intergalactic medium (IGM) in the early Universe ($\\sim$ 400 million years after the Big Bang). The greatest challenge in conventional total-power global 21 cm experiments is the removal of the foreground synchrotron emission ($\\sim 10^3$-$10^4$ K) to uncover the weak cosmological signal (tens to hundreds of mK), especially since the intrinsic smoothness of the foreground spectrum is corrupted by instrumental effects. "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.04917","kind":"arxiv","version":3},"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/1811.04917/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":"2026-07-05T00:07:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1zUsywHunuRH+0hVu76MoBv4o06J2Nhtwv0lGZdcU6RmN//hUxW7En1rhm0Nunctk+AViCE1/jpCVZBYfLNMAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-08T21:45:17.620716Z"},"content_sha256":"f396b4d53530f90df790741daba562bb585e6622224b247fe54873b56425a40e","schema_version":"1.0","event_id":"sha256:f396b4d53530f90df790741daba562bb585e6622224b247fe54873b56425a40e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/bundle.json","state_url":"https://pith.science/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/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":"2026-08-08T21:45:17Z","links":{"resolver":"https://pith.science/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX","bundle":"https://pith.science/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/bundle.json","state":"https://pith.science/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/V5W5NQWDUUDQR7KPAR2KL2G7PX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:V5W5NQWDUUDQR7KPAR2KL2G7PX","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":"bff5f20a7ca919924725d85cfcd37ef898f5a0033eb0e920ad6554d85daa145a","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-11-12T18:56:10Z","title_canon_sha256":"a22a6b0c347e917aa7abb83691b79a1df3f715a159df1da269a427ffebdae8e8"},"schema_version":"1.0","source":{"id":"1811.04917","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1811.04917","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"arxiv_version","alias_value":"1811.04917v3","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1811.04917","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_12","alias_value":"V5W5NQWDUUDQ","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_16","alias_value":"V5W5NQWDUUDQR7KP","created_at":"2026-07-05T00:07:34Z"},{"alias_kind":"pith_short_8","alias_value":"V5W5NQWD","created_at":"2026-07-05T00:07:34Z"}],"graph_snapshots":[{"event_id":"sha256:f396b4d53530f90df790741daba562bb585e6622224b247fe54873b56425a40e","target":"graph","created_at":"2026-07-05T00:07:34Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/1811.04917/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Detecting the cosmological sky-averaged (global) 21 cm signal as a function of observed frequency will provide a powerful tool to study the ionization and thermal history of the intergalactic medium (IGM) in the early Universe ($\\sim$ 400 million years after the Big Bang). The greatest challenge in conventional total-power global 21 cm experiments is the removal of the foreground synchrotron emission ($\\sim 10^3$-$10^4$ K) to uncover the weak cosmological signal (tens to hundreds of mK), especially since the intrinsic smoothness of the foreground spectrum is corrupted by instrumental effects. ","authors_text":"Bang D. Nhan, David D. Bordenave, David Rapetti, Jack O. Burns, Keith Tauscher, Patricia J. Klima, Richard F. Bradley","cross_cats":["astro-ph.CO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-11-12T18:56:10Z","title":"Assessment of the Projection-induced Polarimetry Technique for Constraining the Foreground Spectrum in Global 21 cm Cosmology"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.04917","kind":"arxiv","version":3},"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:b315160091e67ad6d7de4027e430355346fcf8cbdaba466d0afecd35df90f90f","target":"record","created_at":"2026-07-05T00:07:34Z","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":"bff5f20a7ca919924725d85cfcd37ef898f5a0033eb0e920ad6554d85daa145a","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-11-12T18:56:10Z","title_canon_sha256":"a22a6b0c347e917aa7abb83691b79a1df3f715a159df1da269a427ffebdae8e8"},"schema_version":"1.0","source":{"id":"1811.04917","kind":"arxiv","version":3}},"canonical_sha256":"af6dd6c2c3a50708fd4f0474a5e8df7ded4a350ec0fd252f92a7daf2f1e85ccc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"af6dd6c2c3a50708fd4f0474a5e8df7ded4a350ec0fd252f92a7daf2f1e85ccc","first_computed_at":"2026-07-05T00:07:34.748870Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:07:34.748870Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7EXLozmnZYnM77Kf4g7WbflrWW1TvVLZoooJjnfj/uyehjCkQ4KdaorU064PU4HMnSrhf6HedFSA6dPK1bf5Aw==","signature_status":"signed_v1","signed_at":"2026-07-05T00:07:34.749308Z","signed_message":"canonical_sha256_bytes"},"source_id":"1811.04917","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b315160091e67ad6d7de4027e430355346fcf8cbdaba466d0afecd35df90f90f","sha256:f396b4d53530f90df790741daba562bb585e6622224b247fe54873b56425a40e"],"state_sha256":"7a710f3ea29799210d75bb16d4af63addc7103d283e46f69c51406300f1267f9"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hesNoFHpjUdPPVH2TF2x+if+bxIfUeJ3VDPRSzjALDyfKp28DzBl2rhvrNpZm5kswrDtciZYmVYNKOHJX8uTDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-08T21:45:17.624412Z","bundle_sha256":"d5b5b9075a18f3c92e881add5f167b7759d2b1b62d44f8c04af3023148c582ca"}}