{"paper":{"title":"Constraints on Neutrino Physics from DESI DR2 BAO and DR1 Full Shape","license":"http://creativecommons.org/licenses/by/4.0/","headline":"DESI DR2 BAO and DR1 full-shape data plus CMB data tighten the neutrino mass sum upper limit to 0.0642 eV at 95 percent under flat LambdaCDM.","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"A. Aviles, A. Brodzeller, A. Carnero Rosell, A. Cuceu, A. de la Macorra, A. de Mattia, A. Dey, A. Font-Ribera, A. J. Ross, A. Kremin, A. Leauthaud, A. Meisner, A. Menegas, A. P. Cooper, A. Whitford, A. X. Gonzalez-Morales, B. A. Weaver, B. Dey, C. Garcia-Quintero, C. Howlett, C. Lamman, C. Magneville, C. Poppett, C. Ram\\'irez-P\\'erez, C. Ravoux, C. S. Frenk, C. Y\\`eche, C. Zhao, D. Bianchi, D. Brooks, D. Chebat, D. Gonzalez, D. Huterer, D. J. Eisenstein, D. Kirkby, D. Rabinowitz, D. Schlegel, D. Sprayberry, E. Armengaud, E. Burtin, E. Chaussidon, E. Gazta\\~naga, E. Paillas, E. Sanchez, F. J. Castander, F. Prada, F. Sinigaglia, G. Gutierrez, G. Niz, G. Rossi, G. Tarl\\'e, H. E. Noriega, H. Gil-Mar\\'in, H. K. Herrera-Alcantar, H. Rivera-Morales, H. Seo, H. Zou (DESI Collaboration), I. P\\'erez-R\\`afols, J. A. Newman, J. Behera, J. Chaves-Montero, J. E. Forero-Romero, J. Mena-Fern\\'andez, J. Moustakas, J. Rohlf, K. Lodha, K. Naidoo, K. S. Dawson, L. Casas, L. H. Garrison, L. Le Guillou, L. Samushia, L. Verde, M. Abdul-Karim, M. Charles, M. E. Levi, M. Herbold, M. Ishak, M. Landriau, M. Manera, M. M. Pieri, M. Rashkovetskyi, M. Schubnell, M. Vargas-Maga\\~na, M. Walther, M. Wolfson, N. Deiosso, N. Palanque-Delabrouille, O. Alves, O. Lahav, P. Doel, P. Martini, P. Taylor, P. Zarrouk, Q. Li, R. Calderon, R. Canning, R. Kehoe, R. Miquel, R. Zhou, S. Ahlen, S. BenZvi, S. Brieden, S. Cole, S. Ferraro, S. Gontcho A Gontcho, S. He, S. Juneau, S. Nadathur, T. Claybaugh, T. Kisner, T. Tan, U. Andrade, V. Ruhlmann-Kleider, W. Elbers, W. J. Percival, W. L. Matthewson, W. Turner, Z. Ding","submitted_at":"2025-03-18T21:14:18Z","abstract_excerpt":"The Dark Energy Spectroscopic Instrument (DESI) Collaboration has obtained robust measurements of baryon acoustic oscillations (BAO) in the redshift range, $0.1 < z < 4.2$, based on the Lyman-$\\alpha$ forest and galaxies from Data Release 2 (DR2). We combine these measurements with external cosmic microwave background (CMB) data from Planck and ACT to place our tightest constraints yet on the sum of neutrino masses. Assuming the cosmological $\\Lambda$CDM model and three degenerate neutrino states, we find $\\sum m_\\nu<0.0642$ eV (95%) with a marginalized error of $\\sigma(\\sum m_\\nu)=0.020$ eV. "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Assuming the cosmological ΛCDM model and three degenerate neutrino states, we find ∑m_ν<0.0642 eV (95%) with a marginalized error of σ(∑m_ν)=0.020 eV. ... our constraints are in tension with the lower limits derived from neutrino oscillations. ... In the absence of unknown systematics, this finding could be interpreted as a hint of new physics not necessarily related to neutrinos.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that there are no unknown systematics in the DESI BAO or full-shape measurements and that the base ΛCDM model is an adequate description without extensions; the paper itself flags this as the key caveat for interpreting the tension.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"DESI DR2 BAO and full-shape data plus CMB yield ∑m_ν < 0.0642 eV (95% CL) under ΛCDM, in 3σ tension with oscillation lower limits, relaxed to <0.163 eV in w0waCDM.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"DESI DR2 BAO and DR1 full-shape data plus CMB data tighten the neutrino mass sum upper limit to 0.0642 eV at 95 percent under flat LambdaCDM.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"0c0b15ac53ad75516b26538f693da80e40e94ffe24de275ec1502bc20b2ebdce"},"source":{"id":"2503.14744","kind":"arxiv","version":3},"verdict":{"id":"e678b3ad-b9dc-4417-addd-b5df03240573","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T17:42:09.539773Z","strongest_claim":"Assuming the cosmological ΛCDM model and three degenerate neutrino states, we find ∑m_ν<0.0642 eV (95%) with a marginalized error of σ(∑m_ν)=0.020 eV. ... our constraints are in tension with the lower limits derived from neutrino oscillations. ... In the absence of unknown systematics, this finding could be interpreted as a hint of new physics not necessarily related to neutrinos.","one_line_summary":"DESI DR2 BAO and full-shape data plus CMB yield ∑m_ν < 0.0642 eV (95% CL) under ΛCDM, in 3σ tension with oscillation lower limits, relaxed to <0.163 eV in w0waCDM.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that there are no unknown systematics in the DESI BAO or full-shape measurements and that the base ΛCDM model is an adequate description without extensions; the paper itself flags this as the key caveat for interpreting the tension.","pith_extraction_headline":"DESI DR2 BAO and DR1 full-shape data plus CMB data tighten the neutrino mass sum upper limit to 0.0642 eV at 95 percent under flat LambdaCDM."},"references":{"count":223,"sample":[{"doi":"","year":null,"title":"Origin of the anomaly We can trace the origin of the preference for negative effective neutrino masses from DESI BAO and CMB to a number of different effects [73]. 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McClelland, ApJ 180, 7 (1973)","work_id":"764aa55c-8d0d-4995-96ec-2e00e64dd953","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":223,"snapshot_sha256":"9f7576beda32e2d046dd576b81b474986ed65805e2ed8b37a5efa23c977ee7cc","internal_anchors":76},"formal_canon":{"evidence_count":2,"snapshot_sha256":"530bf11cc33c9e125a306134494deaaf379471ee97601c18bbaed19b44042d1c"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}