{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:RWCVTU3CRSHBLSH5ZMD4BS7WA3","short_pith_number":"pith:RWCVTU3C","canonical_record":{"source":{"id":"1807.09287","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-07-24T18:03:52Z","cross_cats_sorted":[],"title_canon_sha256":"69fb039b81f1e552e653bc8c0b1ac5f91dac784679c129d559415dedd70f41e8","abstract_canon_sha256":"1c95844776de4c98576f192564bb648481e327b6d7cfb1907ba50361493cb988"},"schema_version":"1.0"},"canonical_sha256":"8d8559d3628c8e15c8fdcb07c0cbf606c6c9bfbbbfbc0dc9b9e9d919d29fa78e","source":{"kind":"arxiv","id":"1807.09287","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.09287","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"arxiv_version","alias_value":"1807.09287v1","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.09287","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"pith_short_12","alias_value":"RWCVTU3CRSHB","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"RWCVTU3CRSHBLSH5","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"RWCVTU3C","created_at":"2026-05-18T12:32:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:RWCVTU3CRSHBLSH5ZMD4BS7WA3","target":"record","payload":{"canonical_record":{"source":{"id":"1807.09287","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-07-24T18:03:52Z","cross_cats_sorted":[],"title_canon_sha256":"69fb039b81f1e552e653bc8c0b1ac5f91dac784679c129d559415dedd70f41e8","abstract_canon_sha256":"1c95844776de4c98576f192564bb648481e327b6d7cfb1907ba50361493cb988"},"schema_version":"1.0"},"canonical_sha256":"8d8559d3628c8e15c8fdcb07c0cbf606c6c9bfbbbfbc0dc9b9e9d919d29fa78e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:09:51.772653Z","signature_b64":"UvDTQVHwo3xmDG0nB+xrlLHkvtwkXeAPDDdJzyXbnGgNAM3qg3+fXaysF2dj5Q/80a+d/MiDvemZHbcYnI3xDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8d8559d3628c8e15c8fdcb07c0cbf606c6c9bfbbbfbc0dc9b9e9d919d29fa78e","last_reissued_at":"2026-05-18T00:09:51.771969Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:09:51.771969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1807.09287","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":"2026-05-18T00:09:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/u2JF47ybEwzZPkItzgQGbThBa3qIz7/bOVQLRxdymmgC2YiUvU/rTW5eVTbKTldDRYuxiog+4u+BDIFwTYiBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T05:21:08.016302Z"},"content_sha256":"06d7e9813b10422a00b90d9279a32763b9c4556c4628d9384e43c70a13e67241","schema_version":"1.0","event_id":"sha256:06d7e9813b10422a00b90d9279a32763b9c4556c4628d9384e43c70a13e67241"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:RWCVTU3CRSHBLSH5ZMD4BS7WA3","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Overview of the Dark Energy Spectroscopic Instrument","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"Brenna Flaugher, Claire Poppett, Constance Rockosi, Daniel Eisenstein, David Brooks, David J. Schlegel, David Rabinowitz, David Sprayberry, Francisco Prada, Gaston Gutierrez, Jerry Edelstein, Joseph H. Silber, Klaus Honscheid, Laia Cardiel Sas, Michael Levi, Michael Schubnell, Patrick Jelinsky, Paul Martini, Peter Doel, Ray Sharples, Richard Joyce, Risa Wechsler, Robert W. Besuner, Stephen Bailey, Stephen Kent, Stewart E. Harris","submitted_at":"2018-07-24T18:03:52Z","abstract_excerpt":"The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 square degrees will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. We present an overview of the instrumentation, the main technical requirements and challenges, and the current status of the project."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.09287","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":""},"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":"2026-05-18T00:09:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"As/x34ygB7lfzcXxtaGom3lcsNVpMfCzVMECZoLzyW/ttduWyIwDLVRC8ZWymjIyS3VfyNHA9k8dvWq+cv8YBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T05:21:08.016727Z"},"content_sha256":"09ca297bb8aab0f3c89d9af86b32795251c867f27349da8e034916dae0e7e0b7","schema_version":"1.0","event_id":"sha256:09ca297bb8aab0f3c89d9af86b32795251c867f27349da8e034916dae0e7e0b7"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/bundle.json","state_url":"https://pith.science/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/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":"2026-05-30T05:21:08Z","links":{"resolver":"https://pith.science/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3","bundle":"https://pith.science/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/bundle.json","state":"https://pith.science/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/state.json","well_known_bundle":"https://pith.science/.well-known/pith/RWCVTU3CRSHBLSH5ZMD4BS7WA3/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:RWCVTU3CRSHBLSH5ZMD4BS7WA3","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":"1c95844776de4c98576f192564bb648481e327b6d7cfb1907ba50361493cb988","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-07-24T18:03:52Z","title_canon_sha256":"69fb039b81f1e552e653bc8c0b1ac5f91dac784679c129d559415dedd70f41e8"},"schema_version":"1.0","source":{"id":"1807.09287","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.09287","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"arxiv_version","alias_value":"1807.09287v1","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.09287","created_at":"2026-05-18T00:09:51Z"},{"alias_kind":"pith_short_12","alias_value":"RWCVTU3CRSHB","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"RWCVTU3CRSHBLSH5","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"RWCVTU3C","created_at":"2026-05-18T12:32:50Z"}],"graph_snapshots":[{"event_id":"sha256:09ca297bb8aab0f3c89d9af86b32795251c867f27349da8e034916dae0e7e0b7","target":"graph","created_at":"2026-05-18T00:09:51Z","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":"The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 square degrees will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. We present an overview of the instrumentation, the main technical requirements and challenges, and the current status of the project.","authors_text":"Brenna Flaugher, Claire Poppett, Constance Rockosi, Daniel Eisenstein, David Brooks, David J. Schlegel, David Rabinowitz, David Sprayberry, Francisco Prada, Gaston Gutierrez, Jerry Edelstein, Joseph H. Silber, Klaus Honscheid, Laia Cardiel Sas, Michael Levi, Michael Schubnell, Patrick Jelinsky, Paul Martini, Peter Doel, Ray Sharples, Richard Joyce, Risa Wechsler, Robert W. Besuner, Stephen Bailey, Stephen Kent, Stewart E. Harris","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-07-24T18:03:52Z","title":"Overview of the Dark Energy Spectroscopic Instrument"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.09287","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":"sha256:06d7e9813b10422a00b90d9279a32763b9c4556c4628d9384e43c70a13e67241","target":"record","created_at":"2026-05-18T00:09:51Z","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":"1c95844776de4c98576f192564bb648481e327b6d7cfb1907ba50361493cb988","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2018-07-24T18:03:52Z","title_canon_sha256":"69fb039b81f1e552e653bc8c0b1ac5f91dac784679c129d559415dedd70f41e8"},"schema_version":"1.0","source":{"id":"1807.09287","kind":"arxiv","version":1}},"canonical_sha256":"8d8559d3628c8e15c8fdcb07c0cbf606c6c9bfbbbfbc0dc9b9e9d919d29fa78e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8d8559d3628c8e15c8fdcb07c0cbf606c6c9bfbbbfbc0dc9b9e9d919d29fa78e","first_computed_at":"2026-05-18T00:09:51.771969Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:09:51.771969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"UvDTQVHwo3xmDG0nB+xrlLHkvtwkXeAPDDdJzyXbnGgNAM3qg3+fXaysF2dj5Q/80a+d/MiDvemZHbcYnI3xDA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:09:51.772653Z","signed_message":"canonical_sha256_bytes"},"source_id":"1807.09287","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:06d7e9813b10422a00b90d9279a32763b9c4556c4628d9384e43c70a13e67241","sha256:09ca297bb8aab0f3c89d9af86b32795251c867f27349da8e034916dae0e7e0b7"],"state_sha256":"89a7349520636b03913cbeb9885c00b977dd3c399cb66f88acb9ed9578cb7c53"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"78hxAwyYn5UhfdPc9FY/bJxLz7/4t/M2YJTrIzgOcYr+9KOVkJgcXrNFABK398FUqwANBXKdU+O+n7yqgd2mDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T05:21:08.019997Z","bundle_sha256":"edfc58d65cb89931d864bc520214afda2fd090bd3937af42c7093723b9e29d0e"}}