{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:7DBDXVPXW6T7YWWSQQQCN3KI7U","short_pith_number":"pith:7DBDXVPX","canonical_record":{"source":{"id":"2504.13070","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2025-04-17T16:31:14Z","cross_cats_sorted":[],"title_canon_sha256":"dfda841b53e6128cf9de1e934438710c96d51eb209a4399652120e916e135350","abstract_canon_sha256":"3dec1508baeb015a9592a2caf99f8854f0dcf0bb1762f1dbe29088dd64ada641"},"schema_version":"1.0"},"canonical_sha256":"f8c23bd5f7b7a7fc5ad2842026ed48fd22d908400368952565f8eced53feece7","source":{"kind":"arxiv","id":"2504.13070","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.13070","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"arxiv_version","alias_value":"2504.13070v2","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.13070","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_12","alias_value":"7DBDXVPXW6T7","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_16","alias_value":"7DBDXVPXW6T7YWWS","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_8","alias_value":"7DBDXVPX","created_at":"2026-07-05T11:47:21Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:7DBDXVPXW6T7YWWSQQQCN3KI7U","target":"record","payload":{"canonical_record":{"source":{"id":"2504.13070","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2025-04-17T16:31:14Z","cross_cats_sorted":[],"title_canon_sha256":"dfda841b53e6128cf9de1e934438710c96d51eb209a4399652120e916e135350","abstract_canon_sha256":"3dec1508baeb015a9592a2caf99f8854f0dcf0bb1762f1dbe29088dd64ada641"},"schema_version":"1.0"},"canonical_sha256":"f8c23bd5f7b7a7fc5ad2842026ed48fd22d908400368952565f8eced53feece7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:47:21.961127Z","signature_b64":"XPZE9Pm6t98NsislFHZlNLzcMoGzLf70SIv0jDAqlNgQ+YmKEEa4zQ1QMpJL0xaxgDnjgIYCPSsR3SeVcHjpAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f8c23bd5f7b7a7fc5ad2842026ed48fd22d908400368952565f8eced53feece7","last_reissued_at":"2026-07-05T11:47:21.960604Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:47:21.960604Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2504.13070","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":"2026-07-05T11:47:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sxvadT0wj5Iya3sPig//i2i1uyyN11ay8i6kK+r76d96ViKSGIGmuaJ/VVu8Pj7DeK10tfyJKtyCbTTvLY9sCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T06:38:12.676869Z"},"content_sha256":"9b3f2e6a47231f29854f8ed22f6bafab5e44a94f7f7f78d6b4c088191df90145","schema_version":"1.0","event_id":"sha256:9b3f2e6a47231f29854f8ed22f6bafab5e44a94f7f7f78d6b4c088191df90145"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:7DBDXVPXW6T7YWWSQQQCN3KI7U","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A quadratic estimator view of the transfer function correction in intensity mapping surveys","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Zhaoting Chen","submitted_at":"2025-04-17T16:31:14Z","abstract_excerpt":"In single dish neutral hydrogen (HI) intensity mapping, signal separation methods such as principal component analysis (PCA) are used to clean the astrophysical foregrounds. PCA induces a signal loss in the estimated power spectrum, which can be corrected by a transfer function (TF). By injecting mock signals of HI into the data and performing the PCA cleaning, we can use the cleaned mock HI signal to cross-correlate with the original mock, and estimate the signal loss as a TF, ${T}(\\vec{k})$. As expected, a correction of ${T} (\\vec{k})^{-1}$ restores the cross-power between the HI and optical"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.13070","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/2504.13070/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":"2026-07-05T11:47:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"afmb8uFcOguxSYtkS+zr+HoObypq6ZdhAODLIQERIPOuwwmTUfVuja1ZuSOirYKr91uzPI5HJR3bUnj5C3bqCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T06:38:12.677416Z"},"content_sha256":"2ee498cc9ec4a63256b56a0d2e6ed6776a62b41554354b55a62d2204b44bff98","schema_version":"1.0","event_id":"sha256:2ee498cc9ec4a63256b56a0d2e6ed6776a62b41554354b55a62d2204b44bff98"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/bundle.json","state_url":"https://pith.science/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/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":"2026-08-21T06:38:12Z","links":{"resolver":"https://pith.science/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U","bundle":"https://pith.science/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/bundle.json","state":"https://pith.science/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7DBDXVPXW6T7YWWSQQQCN3KI7U/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:7DBDXVPXW6T7YWWSQQQCN3KI7U","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":"3dec1508baeb015a9592a2caf99f8854f0dcf0bb1762f1dbe29088dd64ada641","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2025-04-17T16:31:14Z","title_canon_sha256":"dfda841b53e6128cf9de1e934438710c96d51eb209a4399652120e916e135350"},"schema_version":"1.0","source":{"id":"2504.13070","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.13070","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"arxiv_version","alias_value":"2504.13070v2","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.13070","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_12","alias_value":"7DBDXVPXW6T7","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_16","alias_value":"7DBDXVPXW6T7YWWS","created_at":"2026-07-05T11:47:21Z"},{"alias_kind":"pith_short_8","alias_value":"7DBDXVPX","created_at":"2026-07-05T11:47:21Z"}],"graph_snapshots":[{"event_id":"sha256:2ee498cc9ec4a63256b56a0d2e6ed6776a62b41554354b55a62d2204b44bff98","target":"graph","created_at":"2026-07-05T11:47:21Z","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/2504.13070/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In single dish neutral hydrogen (HI) intensity mapping, signal separation methods such as principal component analysis (PCA) are used to clean the astrophysical foregrounds. PCA induces a signal loss in the estimated power spectrum, which can be corrected by a transfer function (TF). By injecting mock signals of HI into the data and performing the PCA cleaning, we can use the cleaned mock HI signal to cross-correlate with the original mock, and estimate the signal loss as a TF, ${T}(\\vec{k})$. As expected, a correction of ${T} (\\vec{k})^{-1}$ restores the cross-power between the HI and optical","authors_text":"Zhaoting Chen","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2025-04-17T16:31:14Z","title":"A quadratic estimator view of the transfer function correction in intensity mapping surveys"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.13070","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":"sha256:9b3f2e6a47231f29854f8ed22f6bafab5e44a94f7f7f78d6b4c088191df90145","target":"record","created_at":"2026-07-05T11:47:21Z","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":"3dec1508baeb015a9592a2caf99f8854f0dcf0bb1762f1dbe29088dd64ada641","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2025-04-17T16:31:14Z","title_canon_sha256":"dfda841b53e6128cf9de1e934438710c96d51eb209a4399652120e916e135350"},"schema_version":"1.0","source":{"id":"2504.13070","kind":"arxiv","version":2}},"canonical_sha256":"f8c23bd5f7b7a7fc5ad2842026ed48fd22d908400368952565f8eced53feece7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f8c23bd5f7b7a7fc5ad2842026ed48fd22d908400368952565f8eced53feece7","first_computed_at":"2026-07-05T11:47:21.960604Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:47:21.960604Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"XPZE9Pm6t98NsislFHZlNLzcMoGzLf70SIv0jDAqlNgQ+YmKEEa4zQ1QMpJL0xaxgDnjgIYCPSsR3SeVcHjpAw==","signature_status":"signed_v1","signed_at":"2026-07-05T11:47:21.961127Z","signed_message":"canonical_sha256_bytes"},"source_id":"2504.13070","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9b3f2e6a47231f29854f8ed22f6bafab5e44a94f7f7f78d6b4c088191df90145","sha256:2ee498cc9ec4a63256b56a0d2e6ed6776a62b41554354b55a62d2204b44bff98"],"state_sha256":"fd8587af6fa8b7c217bf5dd10747d6b4365b11b18178844e7668579a9e055d3c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"djvxmWK2h6FP86wEEYdiDnZuGf+uPJQO6Qm5CuIPFK4U4qmMPCbfm7VTSmbqUZnMqSrRSt66quF5CPBFtJ11Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-21T06:38:12.681516Z","bundle_sha256":"dbc39477b1723a587ddf343a55e0f4d980e264bcca5ab7096fdc814169f7780d"}}