{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2022:IG7NDC6FMUTFM5QKUL6WDXLYU4","short_pith_number":"pith:IG7NDC6F","canonical_record":{"source":{"id":"2207.02881","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"gr-qc","submitted_at":"2022-07-06T18:00:12Z","cross_cats_sorted":["physics.comp-ph"],"title_canon_sha256":"7f8c8d79c72334449dcd8e75795f387a0c0878f7f0213d625e984525ce9d07de","abstract_canon_sha256":"f8950edaf944d469ba3943e5dbc1cf2b5f2c93bce42e09f5784777c79b8515e2"},"schema_version":"1.0"},"canonical_sha256":"41bed18bc5652656760aa2fd61dd78a73a7cccc32783717f840d327b0fb43496","source":{"kind":"arxiv","id":"2207.02881","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2207.02881","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"arxiv_version","alias_value":"2207.02881v2","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2207.02881","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_12","alias_value":"IG7NDC6FMUTF","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_16","alias_value":"IG7NDC6FMUTFM5QK","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_8","alias_value":"IG7NDC6F","created_at":"2026-07-05T05:52:56Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2022:IG7NDC6FMUTFM5QKUL6WDXLYU4","target":"record","payload":{"canonical_record":{"source":{"id":"2207.02881","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"gr-qc","submitted_at":"2022-07-06T18:00:12Z","cross_cats_sorted":["physics.comp-ph"],"title_canon_sha256":"7f8c8d79c72334449dcd8e75795f387a0c0878f7f0213d625e984525ce9d07de","abstract_canon_sha256":"f8950edaf944d469ba3943e5dbc1cf2b5f2c93bce42e09f5784777c79b8515e2"},"schema_version":"1.0"},"canonical_sha256":"41bed18bc5652656760aa2fd61dd78a73a7cccc32783717f840d327b0fb43496","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T05:52:56.983572Z","signature_b64":"goVEfGkkWS0Sn08RQW8VTxRCyhQZ9qxJOh0iMXH/qVbjxzh92AJvGgqE2AbeF4lB2+euBTD5+dQJGKmcF7qTDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"41bed18bc5652656760aa2fd61dd78a73a7cccc32783717f840d327b0fb43496","last_reissued_at":"2026-07-05T05:52:56.983117Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T05:52:56.983117Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2207.02881","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":"2026-07-05T05:52:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QlmBeyoaVMrUb+NbN9vEKqmjJwNI/X2VyL7b0AdoA/oNyZJIusHfNZEtosLOVZg6iyQWWhy3Tn6F7JBGcly+Cg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-22T14:55:39.609172Z"},"content_sha256":"08a435fa6f564609826e6dc99874ef5e32ddbe668a9cfa7ab30beb390cded636","schema_version":"1.0","event_id":"sha256:08a435fa6f564609826e6dc99874ef5e32ddbe668a9cfa7ab30beb390cded636"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2022:IG7NDC6FMUTFM5QKUL6WDXLYU4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Markov Chain Monte Carlo methods for graph refinement in Spinfoam Cosmology","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["physics.comp-ph"],"primary_cat":"gr-qc","authors_text":"Francesca Vidotto, Francesco Gozzini, Pietropaolo Frisoni","submitted_at":"2022-07-06T18:00:12Z","abstract_excerpt":"We study the behaviour of the Lorentzian Engle-Pereira-Rovelli-Livine spinfoam amplitude with homogeneous boundary data, under a graph refinement going from five to twenty boundary tetrahedra. This can be interpreted as a wave function of the universe, for which we compute boundary geometrical operators, correlation functions and entanglement entropy. The numerical calculation is made possible by adapting the Metropolis-Hastings algorithm, along with recently developed computational methods appropriate for the deep quantum regime. We confirm that the transition amplitudes are stable against su"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2207.02881","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/2207.02881/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":"2026-07-05T05:52:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"PhsIHxdAJ4uo8W0oZib1ZONtgn0s4QYIzFVWjPe4rHcziOP8Rq8OOHPzaRCOg9P8qVmd/4mEcW5CJODkfBe6Bg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-22T14:55:39.609753Z"},"content_sha256":"e72130f44f21ad9705b803bac71fdadad7ad7dd6da0da221c1890b8a28f40fb0","schema_version":"1.0","event_id":"sha256:e72130f44f21ad9705b803bac71fdadad7ad7dd6da0da221c1890b8a28f40fb0"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/bundle.json","state_url":"https://pith.science/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/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":"2026-08-22T14:55:39Z","links":{"resolver":"https://pith.science/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4","bundle":"https://pith.science/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/bundle.json","state":"https://pith.science/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IG7NDC6FMUTFM5QKUL6WDXLYU4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:IG7NDC6FMUTFM5QKUL6WDXLYU4","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":"f8950edaf944d469ba3943e5dbc1cf2b5f2c93bce42e09f5784777c79b8515e2","cross_cats_sorted":["physics.comp-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"gr-qc","submitted_at":"2022-07-06T18:00:12Z","title_canon_sha256":"7f8c8d79c72334449dcd8e75795f387a0c0878f7f0213d625e984525ce9d07de"},"schema_version":"1.0","source":{"id":"2207.02881","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2207.02881","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"arxiv_version","alias_value":"2207.02881v2","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2207.02881","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_12","alias_value":"IG7NDC6FMUTF","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_16","alias_value":"IG7NDC6FMUTFM5QK","created_at":"2026-07-05T05:52:56Z"},{"alias_kind":"pith_short_8","alias_value":"IG7NDC6F","created_at":"2026-07-05T05:52:56Z"}],"graph_snapshots":[{"event_id":"sha256:e72130f44f21ad9705b803bac71fdadad7ad7dd6da0da221c1890b8a28f40fb0","target":"graph","created_at":"2026-07-05T05:52:56Z","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/2207.02881/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We study the behaviour of the Lorentzian Engle-Pereira-Rovelli-Livine spinfoam amplitude with homogeneous boundary data, under a graph refinement going from five to twenty boundary tetrahedra. This can be interpreted as a wave function of the universe, for which we compute boundary geometrical operators, correlation functions and entanglement entropy. The numerical calculation is made possible by adapting the Metropolis-Hastings algorithm, along with recently developed computational methods appropriate for the deep quantum regime. We confirm that the transition amplitudes are stable against su","authors_text":"Francesca Vidotto, Francesco Gozzini, Pietropaolo Frisoni","cross_cats":["physics.comp-ph"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"gr-qc","submitted_at":"2022-07-06T18:00:12Z","title":"Markov Chain Monte Carlo methods for graph refinement in Spinfoam Cosmology"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2207.02881","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":"sha256:08a435fa6f564609826e6dc99874ef5e32ddbe668a9cfa7ab30beb390cded636","target":"record","created_at":"2026-07-05T05:52:56Z","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":"f8950edaf944d469ba3943e5dbc1cf2b5f2c93bce42e09f5784777c79b8515e2","cross_cats_sorted":["physics.comp-ph"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"gr-qc","submitted_at":"2022-07-06T18:00:12Z","title_canon_sha256":"7f8c8d79c72334449dcd8e75795f387a0c0878f7f0213d625e984525ce9d07de"},"schema_version":"1.0","source":{"id":"2207.02881","kind":"arxiv","version":2}},"canonical_sha256":"41bed18bc5652656760aa2fd61dd78a73a7cccc32783717f840d327b0fb43496","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"41bed18bc5652656760aa2fd61dd78a73a7cccc32783717f840d327b0fb43496","first_computed_at":"2026-07-05T05:52:56.983117Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T05:52:56.983117Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"goVEfGkkWS0Sn08RQW8VTxRCyhQZ9qxJOh0iMXH/qVbjxzh92AJvGgqE2AbeF4lB2+euBTD5+dQJGKmcF7qTDg==","signature_status":"signed_v1","signed_at":"2026-07-05T05:52:56.983572Z","signed_message":"canonical_sha256_bytes"},"source_id":"2207.02881","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:08a435fa6f564609826e6dc99874ef5e32ddbe668a9cfa7ab30beb390cded636","sha256:e72130f44f21ad9705b803bac71fdadad7ad7dd6da0da221c1890b8a28f40fb0"],"state_sha256":"04e4c23626dcbb75b09f4f0230deeb347e27b88cf1e23e56aeb1ba5f941b9372"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QY5dsVRRr+L3R+JK7T+4TxDEDV1iioFVqC0DNMUlVlPS1bDkMBy8ac8hhNz8XcqDmxfVwKMZB0O2rddYSTT1DQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-22T14:55:39.614690Z","bundle_sha256":"607e831c1842a510467cfd3f32e42d65da96eed7661ea097eec0e0c6f219f2a2"}}