{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:VYF5EHBX4FIGY5QIIGSOUZABSZ","short_pith_number":"pith:VYF5EHBX","canonical_record":{"source":{"id":"1204.6426","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-04-28T18:10:17Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"81ad815010872c534b1bd3cb53d4dbe055b552740afd7123ad857523bea0ab44","abstract_canon_sha256":"26a27b2096ec861730c3d6e5c97f620e59446a4a764b93924571f991c32248fc"},"schema_version":"1.0"},"canonical_sha256":"ae0bd21c37e1506c760841a4ea6401964962e36a686f0fa432244408da44525f","source":{"kind":"arxiv","id":"1204.6426","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.6426","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"arxiv_version","alias_value":"1204.6426v1","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.6426","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"pith_short_12","alias_value":"VYF5EHBX4FIG","created_at":"2026-05-18T12:27:25Z"},{"alias_kind":"pith_short_16","alias_value":"VYF5EHBX4FIGY5QI","created_at":"2026-05-18T12:27:25Z"},{"alias_kind":"pith_short_8","alias_value":"VYF5EHBX","created_at":"2026-05-18T12:27:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:VYF5EHBX4FIGY5QIIGSOUZABSZ","target":"record","payload":{"canonical_record":{"source":{"id":"1204.6426","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-04-28T18:10:17Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"81ad815010872c534b1bd3cb53d4dbe055b552740afd7123ad857523bea0ab44","abstract_canon_sha256":"26a27b2096ec861730c3d6e5c97f620e59446a4a764b93924571f991c32248fc"},"schema_version":"1.0"},"canonical_sha256":"ae0bd21c37e1506c760841a4ea6401964962e36a686f0fa432244408da44525f","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:57:42.767817Z","signature_b64":"DHOIWw9Dz8LYrr0DLjnbbHHCFEHEtjbNqWzW0wLOhCewS55hA459GRys9E+9ZLzN4aSHdjfywGVP+uGmOm54Dg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ae0bd21c37e1506c760841a4ea6401964962e36a686f0fa432244408da44525f","last_reissued_at":"2026-05-18T01:57:42.767086Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:57:42.767086Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1204.6426","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":"2026-05-18T01:57:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"9NnK+MjKSnGiTm75cRpxRZamGJJb1l9fuRYXhChH4vXIi0DA64UCz32GtVDTw2HZ1EtQStkhJcwBGz32ojPABw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T22:52:38.140472Z"},"content_sha256":"f88214596b7df19bc5d8f837bb1b302885fc45346ff16022b707734ecfc4c755","schema_version":"1.0","event_id":"sha256:f88214596b7df19bc5d8f837bb1b302885fc45346ff16022b707734ecfc4c755"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:VYF5EHBX4FIGY5QIIGSOUZABSZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Constraints on the Optical-IR extragalactic background from gamma-ray absorption studies","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.HE","authors_text":"Luigi Costamante","submitted_at":"2012-04-28T18:10:17Z","abstract_excerpt":"Very high energy (VHE) gamma-rays from extragalactic sources, interacting by gamma-gamma collisions with diffuse intergalactic radiation fields, provide an alternative way to constrain the diffuse background light, completely independent of direct measurements. The limits depend however on our knowledge of the physics of the gamma-ray sources. After clarifying the interplay between background light and VHE spectra, I summarize the extent and validity of the obtainable limits, and where future improvements can be expected."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.6426","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":"2026-05-18T01:57:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UTYyvdgIktWqjZpzhG1ERWUiqFNL2wogwUGo7HMbBoOBNfC43jrhK/c973VAJx1ieeU3l+URA3YbYRZRnxkxCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T22:52:38.141179Z"},"content_sha256":"8f9fd72932f3cbe9292061db13723cfe61cf7bb84318094d3f17c8c880e5de60","schema_version":"1.0","event_id":"sha256:8f9fd72932f3cbe9292061db13723cfe61cf7bb84318094d3f17c8c880e5de60"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/bundle.json","state_url":"https://pith.science/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/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":"2026-06-07T22:52:38Z","links":{"resolver":"https://pith.science/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ","bundle":"https://pith.science/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/bundle.json","state":"https://pith.science/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VYF5EHBX4FIGY5QIIGSOUZABSZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:VYF5EHBX4FIGY5QIIGSOUZABSZ","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":"26a27b2096ec861730c3d6e5c97f620e59446a4a764b93924571f991c32248fc","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-04-28T18:10:17Z","title_canon_sha256":"81ad815010872c534b1bd3cb53d4dbe055b552740afd7123ad857523bea0ab44"},"schema_version":"1.0","source":{"id":"1204.6426","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.6426","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"arxiv_version","alias_value":"1204.6426v1","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.6426","created_at":"2026-05-18T01:57:42Z"},{"alias_kind":"pith_short_12","alias_value":"VYF5EHBX4FIG","created_at":"2026-05-18T12:27:25Z"},{"alias_kind":"pith_short_16","alias_value":"VYF5EHBX4FIGY5QI","created_at":"2026-05-18T12:27:25Z"},{"alias_kind":"pith_short_8","alias_value":"VYF5EHBX","created_at":"2026-05-18T12:27:25Z"}],"graph_snapshots":[{"event_id":"sha256:8f9fd72932f3cbe9292061db13723cfe61cf7bb84318094d3f17c8c880e5de60","target":"graph","created_at":"2026-05-18T01:57:42Z","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":"Very high energy (VHE) gamma-rays from extragalactic sources, interacting by gamma-gamma collisions with diffuse intergalactic radiation fields, provide an alternative way to constrain the diffuse background light, completely independent of direct measurements. The limits depend however on our knowledge of the physics of the gamma-ray sources. After clarifying the interplay between background light and VHE spectra, I summarize the extent and validity of the obtainable limits, and where future improvements can be expected.","authors_text":"Luigi Costamante","cross_cats":["astro-ph.CO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-04-28T18:10:17Z","title":"Constraints on the Optical-IR extragalactic background from gamma-ray absorption studies"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.6426","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:f88214596b7df19bc5d8f837bb1b302885fc45346ff16022b707734ecfc4c755","target":"record","created_at":"2026-05-18T01:57:42Z","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":"26a27b2096ec861730c3d6e5c97f620e59446a4a764b93924571f991c32248fc","cross_cats_sorted":["astro-ph.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-04-28T18:10:17Z","title_canon_sha256":"81ad815010872c534b1bd3cb53d4dbe055b552740afd7123ad857523bea0ab44"},"schema_version":"1.0","source":{"id":"1204.6426","kind":"arxiv","version":1}},"canonical_sha256":"ae0bd21c37e1506c760841a4ea6401964962e36a686f0fa432244408da44525f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ae0bd21c37e1506c760841a4ea6401964962e36a686f0fa432244408da44525f","first_computed_at":"2026-05-18T01:57:42.767086Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:57:42.767086Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"DHOIWw9Dz8LYrr0DLjnbbHHCFEHEtjbNqWzW0wLOhCewS55hA459GRys9E+9ZLzN4aSHdjfywGVP+uGmOm54Dg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:57:42.767817Z","signed_message":"canonical_sha256_bytes"},"source_id":"1204.6426","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f88214596b7df19bc5d8f837bb1b302885fc45346ff16022b707734ecfc4c755","sha256:8f9fd72932f3cbe9292061db13723cfe61cf7bb84318094d3f17c8c880e5de60"],"state_sha256":"f70a489bad8301a720fdf79473780ff5707e264f9fe9a96ad6f130b7cf50cdd2"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"v6AgDHTEQem4nvzEp3W7kt0T4fkd6rq7qXiDGGfzgiOLNJLEH2YwEOv6SBoLB7UFd7gHXy4T1Aw6M92pq49aDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-07T22:52:38.145762Z","bundle_sha256":"76bfaa8c50c6a89054493525bc910da360919eda40bc5c45f527e137303c77db"}}