{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:35KHHMNLFRGOXDR6T2KSWLX2VG","short_pith_number":"pith:35KHHMNL","canonical_record":{"source":{"id":"1901.08679","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2019-01-24T23:12:29Z","cross_cats_sorted":[],"title_canon_sha256":"729212876dbe58bed5c267a96a3961e9885ba7490150ccf1c02f5da195a21501","abstract_canon_sha256":"18fa3844745fd01e549e67cb309a1dd7aa928a365365bb2a2fbc4dde4e54e4b4"},"schema_version":"1.0"},"canonical_sha256":"df5473b1ab2c4ceb8e3e9e952b2efaa981272c79e59dd0ecf612fa4a7782c20e","source":{"kind":"arxiv","id":"1901.08679","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.08679","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"arxiv_version","alias_value":"1901.08679v2","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.08679","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"pith_short_12","alias_value":"35KHHMNLFRGO","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"35KHHMNLFRGOXDR6","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"35KHHMNL","created_at":"2026-05-18T12:33:07Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:35KHHMNLFRGOXDR6T2KSWLX2VG","target":"record","payload":{"canonical_record":{"source":{"id":"1901.08679","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2019-01-24T23:12:29Z","cross_cats_sorted":[],"title_canon_sha256":"729212876dbe58bed5c267a96a3961e9885ba7490150ccf1c02f5da195a21501","abstract_canon_sha256":"18fa3844745fd01e549e67cb309a1dd7aa928a365365bb2a2fbc4dde4e54e4b4"},"schema_version":"1.0"},"canonical_sha256":"df5473b1ab2c4ceb8e3e9e952b2efaa981272c79e59dd0ecf612fa4a7782c20e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:43:09.133393Z","signature_b64":"5LTh4f2iCylXjo7He+6ZQqWYn3zlflMqLnhK4V5BFaMOqi1XN1Ddl8SC5twDArCb3FT5MR2cVOxPy74RbjYuCw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"df5473b1ab2c4ceb8e3e9e952b2efaa981272c79e59dd0ecf612fa4a7782c20e","last_reissued_at":"2026-05-17T23:43:09.132909Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:43:09.132909Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1901.08679","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":"2026-05-17T23:43:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ijTpiAn49nAaMl2NEQcb5nAZkTs9do01bR+lhf2sgrwOqSD59BYzI9vzHnW1iOeZ/jsyoufenY61VVbd+4bIAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T16:29:56.644306Z"},"content_sha256":"2c0919244b9c01bc5279f3c29b960534727d5685ff2549cf9c3293108f3594ed","schema_version":"1.0","event_id":"sha256:2c0919244b9c01bc5279f3c29b960534727d5685ff2549cf9c3293108f3594ed"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:35KHHMNLFRGOXDR6T2KSWLX2VG","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Fourier-series expansion of the dark-energy equation of state","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"David Tamayo, J. Alberto Vazquez","submitted_at":"2019-01-24T23:12:29Z","abstract_excerpt":"The dark energy component of the universe still remains as a mystery, however, several papers based on observational data have shown that its equation of state may have an oscillatory behaviour. In this paper, we provide a general description for the dark-energy equation-of-state $w(z)$ in the form of Fourier series. This description generalises some previous dynamical dark energy models and is in agreement with the $w(z)$ reconstructions. We make use of a modified version of a simple and fast Markov Chain Monte Carlo code to constraint the model parameters. For the analysis we use data from s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.08679","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":""},"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":"2026-05-17T23:43:09Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wyVbzJiNC7TSWzcngp+t2ZgxX+m0x4JegYaR0HLvZ18k26XLjnGPkVPQc5XfHXRqI6DTjtTHy7MIPtehdfmrBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T16:29:56.645001Z"},"content_sha256":"dcd05cd92683ee7d5544edfdd5afcd5926048e41bc051e1e00ccdca3d3492208","schema_version":"1.0","event_id":"sha256:dcd05cd92683ee7d5544edfdd5afcd5926048e41bc051e1e00ccdca3d3492208"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/bundle.json","state_url":"https://pith.science/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/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":"2026-05-26T16:29:56Z","links":{"resolver":"https://pith.science/pith/35KHHMNLFRGOXDR6T2KSWLX2VG","bundle":"https://pith.science/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/bundle.json","state":"https://pith.science/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/state.json","well_known_bundle":"https://pith.science/.well-known/pith/35KHHMNLFRGOXDR6T2KSWLX2VG/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:35KHHMNLFRGOXDR6T2KSWLX2VG","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":"18fa3844745fd01e549e67cb309a1dd7aa928a365365bb2a2fbc4dde4e54e4b4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2019-01-24T23:12:29Z","title_canon_sha256":"729212876dbe58bed5c267a96a3961e9885ba7490150ccf1c02f5da195a21501"},"schema_version":"1.0","source":{"id":"1901.08679","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1901.08679","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"arxiv_version","alias_value":"1901.08679v2","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1901.08679","created_at":"2026-05-17T23:43:09Z"},{"alias_kind":"pith_short_12","alias_value":"35KHHMNLFRGO","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"35KHHMNLFRGOXDR6","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"35KHHMNL","created_at":"2026-05-18T12:33:07Z"}],"graph_snapshots":[{"event_id":"sha256:dcd05cd92683ee7d5544edfdd5afcd5926048e41bc051e1e00ccdca3d3492208","target":"graph","created_at":"2026-05-17T23:43:09Z","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 component of the universe still remains as a mystery, however, several papers based on observational data have shown that its equation of state may have an oscillatory behaviour. In this paper, we provide a general description for the dark-energy equation-of-state $w(z)$ in the form of Fourier series. This description generalises some previous dynamical dark energy models and is in agreement with the $w(z)$ reconstructions. We make use of a modified version of a simple and fast Markov Chain Monte Carlo code to constraint the model parameters. For the analysis we use data from s","authors_text":"David Tamayo, J. Alberto Vazquez","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2019-01-24T23:12:29Z","title":"Fourier-series expansion of the dark-energy equation of state"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.08679","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":"sha256:2c0919244b9c01bc5279f3c29b960534727d5685ff2549cf9c3293108f3594ed","target":"record","created_at":"2026-05-17T23:43:09Z","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":"18fa3844745fd01e549e67cb309a1dd7aa928a365365bb2a2fbc4dde4e54e4b4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2019-01-24T23:12:29Z","title_canon_sha256":"729212876dbe58bed5c267a96a3961e9885ba7490150ccf1c02f5da195a21501"},"schema_version":"1.0","source":{"id":"1901.08679","kind":"arxiv","version":2}},"canonical_sha256":"df5473b1ab2c4ceb8e3e9e952b2efaa981272c79e59dd0ecf612fa4a7782c20e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"df5473b1ab2c4ceb8e3e9e952b2efaa981272c79e59dd0ecf612fa4a7782c20e","first_computed_at":"2026-05-17T23:43:09.132909Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:43:09.132909Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"5LTh4f2iCylXjo7He+6ZQqWYn3zlflMqLnhK4V5BFaMOqi1XN1Ddl8SC5twDArCb3FT5MR2cVOxPy74RbjYuCw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:43:09.133393Z","signed_message":"canonical_sha256_bytes"},"source_id":"1901.08679","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:2c0919244b9c01bc5279f3c29b960534727d5685ff2549cf9c3293108f3594ed","sha256:dcd05cd92683ee7d5544edfdd5afcd5926048e41bc051e1e00ccdca3d3492208"],"state_sha256":"8663d43d2c2c4b5d1ac7132ba10c3bafffce96ad5a501e911f9814e2bb3e34e1"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0+WKKd7YxjCMZrkTEXQahQ9OTdqHpRwfwYiaIe1MrL7JAO3w5XH88vP83geaiZVOLmiULFtQtOmIZHM9WTs2AA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T16:29:56.648613Z","bundle_sha256":"98db9d01445dbc70ab6f3b68b38bf3ca7dea8e3ade4044dae290b6c98e3367ef"}}