{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:OB2AITXWUJRIYNQ2ZS4ZPKWBY6","short_pith_number":"pith:OB2AITXW","canonical_record":{"source":{"id":"1907.13090","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-29T16:42:21Z","cross_cats_sorted":[],"title_canon_sha256":"15b7e15df73d4d09563aca0cc8194d08cbadc4960dd5fb4aba040ad0864436d9","abstract_canon_sha256":"f0582c39eea15b80af52e1bb0393fe2659b6ae00f91e9c4465414a6735d3ce71"},"schema_version":"1.0"},"canonical_sha256":"7074044ef6a2628c361accb997aac1c7a66c3b046d824a27bb555a0ce5bb0906","source":{"kind":"arxiv","id":"1907.13090","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.13090","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"arxiv_version","alias_value":"1907.13090v1","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.13090","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_12","alias_value":"OB2AITXWUJRI","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_16","alias_value":"OB2AITXWUJRIYNQ2","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_8","alias_value":"OB2AITXW","created_at":"2026-07-04T23:50:28Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:OB2AITXWUJRIYNQ2ZS4ZPKWBY6","target":"record","payload":{"canonical_record":{"source":{"id":"1907.13090","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-29T16:42:21Z","cross_cats_sorted":[],"title_canon_sha256":"15b7e15df73d4d09563aca0cc8194d08cbadc4960dd5fb4aba040ad0864436d9","abstract_canon_sha256":"f0582c39eea15b80af52e1bb0393fe2659b6ae00f91e9c4465414a6735d3ce71"},"schema_version":"1.0"},"canonical_sha256":"7074044ef6a2628c361accb997aac1c7a66c3b046d824a27bb555a0ce5bb0906","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T23:50:28.245039Z","signature_b64":"WTdSvVHaDPqMYDkLRGHjse1MXrkx+ZMEqieb8L5TVQSVwMVvZvcNrsFm+qpquNWchqMdux52Y15GSPVyKxkjAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7074044ef6a2628c361accb997aac1c7a66c3b046d824a27bb555a0ce5bb0906","last_reissued_at":"2026-07-04T23:50:28.244605Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T23:50:28.244605Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1907.13090","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T23:50:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/ILb+g78IZaUCTGTH1oYL76dRF1lYdfbagbTDOqgtCwx+kXHCBAk7nRXPRZ6owu5hPTW7rb02ubbnRU7m+9hBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T08:05:57.182590Z"},"content_sha256":"d3baaaed470f7bc353904aebf0a03449d8a734003995e0080fae204a83d49678","schema_version":"1.0","event_id":"sha256:d3baaaed470f7bc353904aebf0a03449d8a734003995e0080fae204a83d49678"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:OB2AITXWUJRIYNQ2ZS4ZPKWBY6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Research and Development for HI Intensity Mapping","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"Aaron Ewall-Wice, Adam Beardsley, Adrian Liu, Albert Stebbins, Alexander A. Kaurov, Alexander van Engelen, Andrei Nomerotski, Andrej Obuljen, An\\v{z}e Slosar, Benjamin Saliwanchik, Chris Sheehy, Dallas Wulf, Daniel Green, Daniel Jacobs, David Alonso, David Parkinson, David Rapetti, Dionysios Karagiannis, Emanuele Castorina, Emily Kuhn, Erin Sheldon, Evan J. Arena, Eva Silverstein, Francisco Villaescusa-Navarro, Gilbert Holder, Gregory S. Tucker, Hamsa Padmanabhan, Josef Frisch, Joshua S. Dillon, J. Richard Shaw, Kavilan Moodley, Kevin Bandura, Kiyoshi W. Masui, Laura B. Newburgh, Lloyd Knox, Moritz M\\\"unchmeyer, Mustafa A. Amin, Neelima Sehgal, Olivier Perdereau, Paul O'Connor, Paul Stankus, Peter Timbie, Philip Bull, Raphael Shirley, R\\'eza Ansari, Romeel Dav\\'e, Simone Ferraro, Simon Foreman, Thomas McClintock, Tracy Slatyer, Tzu-Ching Chang, William Tyndall, Yin-Zhe Ma, Zeeshan Ahmed","submitted_at":"2019-07-29T16:42:21Z","abstract_excerpt":"Development of the hardware, data analysis, and simulation techniques for large compact radio arrays dedicated to mapping the 21 cm line of neutral hydrogen gas has proven to be more difficult than imagined twenty years ago when such telescopes were first proposed. Despite tremendous technical and methodological advances, there are several outstanding questions on how to optimally calibrate and analyze such data. On the positive side, it has become clear that the outstanding issues are purely technical in nature and can be solved with sufficient development activity. Such activity will enable "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.13090","kind":"arxiv","version":1},"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/1907.13090/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":"2026-07-04T23:50:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ecCANvj+8Blu9wvIE7EsgoO5NwYsl5QFeMzd1FnGK3XM02ZPY7xAlqmNwLbDfTvq9YRpdujbvAwOVpBXlun/AQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T08:05:57.182965Z"},"content_sha256":"babc386ae214d8a1a401cfe48b927d43d37f923348c5b1dde9c448744f10a0da","schema_version":"1.0","event_id":"sha256:babc386ae214d8a1a401cfe48b927d43d37f923348c5b1dde9c448744f10a0da"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/bundle.json","state_url":"https://pith.science/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/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":"2026-07-05T08:05:57Z","links":{"resolver":"https://pith.science/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6","bundle":"https://pith.science/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/bundle.json","state":"https://pith.science/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OB2AITXWUJRIYNQ2ZS4ZPKWBY6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:OB2AITXWUJRIYNQ2ZS4ZPKWBY6","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":"f0582c39eea15b80af52e1bb0393fe2659b6ae00f91e9c4465414a6735d3ce71","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-29T16:42:21Z","title_canon_sha256":"15b7e15df73d4d09563aca0cc8194d08cbadc4960dd5fb4aba040ad0864436d9"},"schema_version":"1.0","source":{"id":"1907.13090","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.13090","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"arxiv_version","alias_value":"1907.13090v1","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.13090","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_12","alias_value":"OB2AITXWUJRI","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_16","alias_value":"OB2AITXWUJRIYNQ2","created_at":"2026-07-04T23:50:28Z"},{"alias_kind":"pith_short_8","alias_value":"OB2AITXW","created_at":"2026-07-04T23:50:28Z"}],"graph_snapshots":[{"event_id":"sha256:babc386ae214d8a1a401cfe48b927d43d37f923348c5b1dde9c448744f10a0da","target":"graph","created_at":"2026-07-04T23:50:28Z","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/1907.13090/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Development of the hardware, data analysis, and simulation techniques for large compact radio arrays dedicated to mapping the 21 cm line of neutral hydrogen gas has proven to be more difficult than imagined twenty years ago when such telescopes were first proposed. Despite tremendous technical and methodological advances, there are several outstanding questions on how to optimally calibrate and analyze such data. On the positive side, it has become clear that the outstanding issues are purely technical in nature and can be solved with sufficient development activity. Such activity will enable ","authors_text":"Aaron Ewall-Wice, Adam Beardsley, Adrian Liu, Albert Stebbins, Alexander A. Kaurov, Alexander van Engelen, Andrei Nomerotski, Andrej Obuljen, An\\v{z}e Slosar, Benjamin Saliwanchik, Chris Sheehy, Dallas Wulf, Daniel Green, Daniel Jacobs, David Alonso, David Parkinson, David Rapetti, Dionysios Karagiannis, Emanuele Castorina, Emily Kuhn, Erin Sheldon, Evan J. Arena, Eva Silverstein, Francisco Villaescusa-Navarro, Gilbert Holder, Gregory S. Tucker, Hamsa Padmanabhan, Josef Frisch, Joshua S. Dillon, J. Richard Shaw, Kavilan Moodley, Kevin Bandura, Kiyoshi W. Masui, Laura B. Newburgh, Lloyd Knox, Moritz M\\\"unchmeyer, Mustafa A. Amin, Neelima Sehgal, Olivier Perdereau, Paul O'Connor, Paul Stankus, Peter Timbie, Philip Bull, Raphael Shirley, R\\'eza Ansari, Romeel Dav\\'e, Simone Ferraro, Simon Foreman, Thomas McClintock, Tracy Slatyer, Tzu-Ching Chang, William Tyndall, Yin-Zhe Ma, Zeeshan Ahmed","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-29T16:42:21Z","title":"Research and Development for HI Intensity Mapping"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.13090","kind":"arxiv","version":1},"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:d3baaaed470f7bc353904aebf0a03449d8a734003995e0080fae204a83d49678","target":"record","created_at":"2026-07-04T23:50:28Z","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":"f0582c39eea15b80af52e1bb0393fe2659b6ae00f91e9c4465414a6735d3ce71","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2019-07-29T16:42:21Z","title_canon_sha256":"15b7e15df73d4d09563aca0cc8194d08cbadc4960dd5fb4aba040ad0864436d9"},"schema_version":"1.0","source":{"id":"1907.13090","kind":"arxiv","version":1}},"canonical_sha256":"7074044ef6a2628c361accb997aac1c7a66c3b046d824a27bb555a0ce5bb0906","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7074044ef6a2628c361accb997aac1c7a66c3b046d824a27bb555a0ce5bb0906","first_computed_at":"2026-07-04T23:50:28.244605Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T23:50:28.244605Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"WTdSvVHaDPqMYDkLRGHjse1MXrkx+ZMEqieb8L5TVQSVwMVvZvcNrsFm+qpquNWchqMdux52Y15GSPVyKxkjAQ==","signature_status":"signed_v1","signed_at":"2026-07-04T23:50:28.245039Z","signed_message":"canonical_sha256_bytes"},"source_id":"1907.13090","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d3baaaed470f7bc353904aebf0a03449d8a734003995e0080fae204a83d49678","sha256:babc386ae214d8a1a401cfe48b927d43d37f923348c5b1dde9c448744f10a0da"],"state_sha256":"413af987211f04070b9539176531e1816d2a07e2c458d627e70a7b0e4e6fdaa8"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"D9MFOvWYMqaAq20hpJ5Fp7AfXwgwehr465smUMoTF+V3zh0Gxo4bna40+ac4G+j709ZqqBcRp2tledlW3zwNAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-05T08:05:57.184874Z","bundle_sha256":"7ce84514b770133ea8c765ab92699e090f67e23a94384f66bdd36d3b96810dd8"}}