{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2026:IEUZIUNQVMX6FSKVT3KZBV3IEE","short_pith_number":"pith:IEUZIUNQ","schema_version":"1.0","canonical_sha256":"41299451b0ab2fe2c9559ed590d768211e67380129404c7f0b910288e8ba42cf","source":{"kind":"arxiv","id":"2602.12347","version":2},"attestation_state":"computed","paper":{"title":"Sign-Switching Dark Energy: Smooth Transitions with Recent DESI DR2 Observations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Sign-switching dark energy models reduce the Hubble tension and fit DESI DR2 observations better than standard ΛCDM.","cross_cats":["gr-qc","hep-ph","hep-th"],"primary_cat":"astro-ph.CO","authors_text":"Be\\~nat Ibarra-Uriondo, Mariam Bouhmadi-L\\'opez","submitted_at":"2026-02-12T19:08:27Z","abstract_excerpt":"Sign-switching dark energy provides a novel mechanism for modifying the late-time expansion history of the Universe without invoking additional fields or finely tuned initial conditions. In this work, we investigate a class of background--level cosmological models in which the dark energy contribution changes sign at a transition redshift $z_\\dagger$, producing a sharp deviation from standard $\\Lambda$CDM dynamics. We confront these models with a comprehensive set of cosmological observations, including Planck 18 cosmic microwave background (CMB) measurements, DESI DR2 Baryonic Acoustic Oscill"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":true,"formal_links_present":true},"canonical_record":{"source":{"id":"2602.12347","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2026-02-12T19:08:27Z","cross_cats_sorted":["gr-qc","hep-ph","hep-th"],"title_canon_sha256":"70c19d6eb0c1cb852ec6ae212181b4f49ac165938c4cdb1c8c980ea30d4abd60","abstract_canon_sha256":"acd864b2e4ed923505cdf6e8c31ec70fb73e3b4447bd88d272f038478c3807d2"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:38:59.953415Z","signature_b64":"xdWy2wWC3J0TT8skB7tjI34jjfzn8N4ZKG3Yn7seQoAES7Rt5q9kkrEb4NGe6F51RbvU5VHSty0itdWFSsMxBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"41299451b0ab2fe2c9559ed590d768211e67380129404c7f0b910288e8ba42cf","last_reissued_at":"2026-05-17T23:38:59.952665Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:38:59.952665Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Sign-Switching Dark Energy: Smooth Transitions with Recent DESI DR2 Observations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Sign-switching dark energy models reduce the Hubble tension and fit DESI DR2 observations better than standard ΛCDM.","cross_cats":["gr-qc","hep-ph","hep-th"],"primary_cat":"astro-ph.CO","authors_text":"Be\\~nat Ibarra-Uriondo, Mariam Bouhmadi-L\\'opez","submitted_at":"2026-02-12T19:08:27Z","abstract_excerpt":"Sign-switching dark energy provides a novel mechanism for modifying the late-time expansion history of the Universe without invoking additional fields or finely tuned initial conditions. In this work, we investigate a class of background--level cosmological models in which the dark energy contribution changes sign at a transition redshift $z_\\dagger$, producing a sharp deviation from standard $\\Lambda$CDM dynamics. We confront these models with a comprehensive set of cosmological observations, including Planck 18 cosmic microwave background (CMB) measurements, DESI DR2 Baryonic Acoustic Oscill"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"the sign-switching scenario significantly alleviates the Hubble tension while obtaining better results when statistically comparing with ΛCDM, as quantified by the Akaike and Bayesian information Criteria.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The model is explored only at the background level, so the assumption that perturbations around the sign switch do not spoil the fit or introduce new tensions with structure-formation data must hold.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Sign-switching dark energy with a transition at z_† fits recent DESI DR2, Planck CMB, and Pantheon+ data better than ΛCDM while raising the inferred Hubble constant and easing the Hubble tension.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Sign-switching dark energy models reduce the Hubble tension and fit DESI DR2 observations better than standard ΛCDM.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"b154d3896fa46b6057386a190bf32235ad87e9bd743d736817c27079ef434717"},"source":{"id":"2602.12347","kind":"arxiv","version":2},"verdict":{"id":"8e183ec3-c21f-457d-ba18-76a8b8d1a119","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T05:15:21.548155Z","strongest_claim":"the sign-switching scenario significantly alleviates the Hubble tension while obtaining better results when statistically comparing with ΛCDM, as quantified by the Akaike and Bayesian information Criteria.","one_line_summary":"Sign-switching dark energy with a transition at z_† fits recent DESI DR2, Planck CMB, and Pantheon+ data better than ΛCDM while raising the inferred Hubble constant and easing the Hubble tension.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The model is explored only at the background level, so the assumption that perturbations around the sign switch do not spoil the fit or introduce new tensions with structure-formation data must hold.","pith_extraction_headline":"Sign-switching dark energy models reduce the Hubble tension and fit DESI DR2 observations better than standard ΛCDM."},"references":{"count":124,"sample":[{"doi":"","year":null,"title":"Although BAO data are also sensitive to Ω m, an additional prior is required to fully break the degeneracy between the expansion rate and the sound-horizon scale","work_id":"7355d246-e5cc-4c45-aba0-30c9e4420194","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2018,"title":"Baryon Acoustic Oscillations BAO constitute a powerful observational probe for constraining cosmological parameters, particularly when combined with complementary datasets such as the CMB. The charact","work_id":"f62f286c-348e-4ea7-8714-e1c4bd777aca","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Cosmic Microwave Background The CMB is one of the most powerful observational tools for studying the early Universe, carrying detailed information about cosmological evolution from the epoch of photon","work_id":"bd008f6a-1b02-462d-a6b3-975c45e6c6a8","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Fitting the models to these data reveals a significant shift in the inferred value ofH 0 relative to ΛCDM","work_id":"0fe9cf54-ca96-4d3e-b896-c3f73fbc8c4b","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"The parametersH 0 and Ω m0 appear to increase across all models relative to ΛCDM, particularly in LΛCDM and SSCDM","work_id":"32883c5c-0e80-4c2b-be0e-a9a7443535a1","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":124,"snapshot_sha256":"0181fcf4783b90b38e0639528e21d0e1ff23f9324cba8be0934301ae5cc7be61","internal_anchors":46},"formal_canon":{"evidence_count":2,"snapshot_sha256":"cc6fc8405e3e483b2df49e8aa10a1438d784ac43439697222b78cf2b3aa51ac6"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"2602.12347","created_at":"2026-05-17T23:38:59.952795+00:00"},{"alias_kind":"arxiv_version","alias_value":"2602.12347v2","created_at":"2026-05-17T23:38:59.952795+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2602.12347","created_at":"2026-05-17T23:38:59.952795+00:00"},{"alias_kind":"pith_short_12","alias_value":"IEUZIUNQVMX6","created_at":"2026-05-18T12:33:37.589309+00:00"},{"alias_kind":"pith_short_16","alias_value":"IEUZIUNQVMX6FSKV","created_at":"2026-05-18T12:33:37.589309+00:00"},{"alias_kind":"pith_short_8","alias_value":"IEUZIUNQ","created_at":"2026-05-18T12:33:37.589309+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":4,"internal_anchor_count":4,"sample":[{"citing_arxiv_id":"2605.22309","citing_title":"Signatures of Modified Gravity Below $\\mathcal{O}(10)$ Mpc in a Dynamical Dark Energy Background","ref_index":68,"is_internal_anchor":true},{"citing_arxiv_id":"2603.26560","citing_title":"Exploring the interplay of late-time dynamical dark energy and new physics before recombination","ref_index":68,"is_internal_anchor":true},{"citing_arxiv_id":"2604.12032","citing_title":"Constraints on Coupled Dark Energy in the DESI Era","ref_index":53,"is_internal_anchor":true},{"citing_arxiv_id":"2604.12987","citing_title":"Do equation of state parametrizations of dark energy faithfully capture the dynamics of the late universe?","ref_index":65,"is_internal_anchor":true}]},"formal_canon":{"evidence_count":2,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE","json":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE.json","graph_json":"https://pith.science/api/pith-number/IEUZIUNQVMX6FSKVT3KZBV3IEE/graph.json","events_json":"https://pith.science/api/pith-number/IEUZIUNQVMX6FSKVT3KZBV3IEE/events.json","paper":"https://pith.science/paper/IEUZIUNQ"},"agent_actions":{"view_html":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE","download_json":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE.json","view_paper":"https://pith.science/paper/IEUZIUNQ","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2602.12347&json=true","fetch_graph":"https://pith.science/api/pith-number/IEUZIUNQVMX6FSKVT3KZBV3IEE/graph.json","fetch_events":"https://pith.science/api/pith-number/IEUZIUNQVMX6FSKVT3KZBV3IEE/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE/action/timestamp_anchor","attest_storage":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE/action/storage_attestation","attest_author":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE/action/author_attestation","sign_citation":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE/action/citation_signature","submit_replication":"https://pith.science/pith/IEUZIUNQVMX6FSKVT3KZBV3IEE/action/replication_record"}},"created_at":"2026-05-17T23:38:59.952795+00:00","updated_at":"2026-05-17T23:38:59.952795+00:00"}