Article

Dynamical dark energy in light of the DESI DR2 baryonic acoustic oscillations measurements

Gan GuBeijing, Inst. High Energy PhysXiaoma WangNational Astronomical Observatories, Chinese Academy of Sciences, Beijing, People's Republic of ChinaYuting WangInstitute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing, People's Republic of ChinaGong‐Bo ZhaoInstitute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing, People's Republic of ChinaLevon PogosianDepartment of Physics, Simon Fraser University, Burnaby, British Columbia CanadaK. KoyamaInstitute of Cosmology & Gravitation, University of Portsmouth, Portsmouth, UKJ. A. PeacockInstitute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UKZheng CaiDepartment of Astronomy, Tsinghua University, Beijing, People's Republic of ChinaJorge L. Cervantes–CotaDepartamento de Física, Instituto Nacional de Investigaciones Nucleares, Mexico City, MexicoMustapha IshakDepartment of Physics, The University of Texas at Dallas, Richardson, TX USAArman ShafielooKorea Astronomy and Space Science Institute, Daejeon, Republic of KoreaRuiyang ZhaoBeijing, Inst. High Energy PhysS. AhlenPhysics Department, Boston University, Boston, MA USADavide BianchiDipartimento di Fisica 'Aldo Pontremoli', Università degli Studi di Milano, Milan, ItalyDavid BrooksDepartment of Physics & Astronomy, University College London, London, UKT. ClaybaughLawrence Berkeley National Laboratory, Berkeley, CA USAShaun ColeInstitute for Computational Cosmology, Department of Physics, Durham University, Durham, UKAxel de la MacorraInstituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria, Mexico City, MexicoArnaud de MattiaIRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, FranceP. DoelDepartment of Physics & Astronomy, University College London, London, UKS. FerraroLawrence Berkeley National Laboratory, Berkeley, CA USAJ. E. Forero-RomeroDepartamento de Física, Universidad de los Andes, Bogotá, ColombiaE. GaztañagaInstitut d'Estudis Espacials de Catalunya (IEEC), Castelldefels, SpainSatya Gontcho A GontchoLawrence Berkeley National Laboratory, Berkeley, CA USAG. GutiérrezFermi National Accelerator Laboratory, Batavia, IL USAChang Hoon HahnSteward Observatory, University of Arizona, Tucson, AZ USACullan HowlettSchool of Mathematics and Physics, University of Queensland, Brisbane, Queensland AustraliaR. KehoeDepartment of Physics, Southern Methodist University, Dallas, TX USAD. KirkbyDepartment of Physics and Astronomy, University of California, Irvine, CA USAJean‐Paul KneibInstitute of Physics, Laboratory of Astrophysics, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, Versoix, SwitzerlandAnthony KreminLawrence Berkeley National Laboratory, Berkeley, CA USAO. LahavDepartment of Physics & Astronomy, University College London, London, UKMartin LandriauLawrence Berkeley National Laboratory, Berkeley, CA USAL. Le GuillouLaboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Sorbonne Université, CNRS/IN2P3, Paris, FranceAlexie LeauthaudDepartment of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, Santa Cruz, CA USAM. E. LeviLawrence Berkeley National Laboratory, Berkeley, CA USAMarc ManeraDepartament de Física, Serra Húnter, Universitat Autònoma de Barcelona, Barcelona, SpainAaron MeisnerNSF NOIRLab, Tucson, AZ USAR. MiquelInstitució Catalana de Recerca i Estudis Avançats, Barcelona, SpainJohn MoustakasDepartment of Physics and Astronomy, Siena College, Loudonville, NY USAA. Muñoz-GutiérrezInstituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria, Mexico City, MexicoS. NadathurInstitute of Cosmology & Gravitation, University of Portsmouth, Portsmouth, UKJeffrey A. NewmanDepartment of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), University of Pittsburgh, Pittsburgh, PA USAN. Palanque‐DelabrouilleIRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, FranceWill J. PercivalDepartment of Physics and Astronomy, University of Waterloo, Waterloo, Ontario CanadaFrancisco PradaInstituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía, Granada, SpainIgnasi Pérez-RàfolsDepartament de Física, EEBE, Universitat Politècnica de Catalunya, Barcelona, SpainGraziano RossiDepartment of Physics and Astronomy, Sejong University, Seoul, Republic of KoreaLado SamushiaAbastumani Astrophysical Observatory, Tbilisi, GeorgiaE. SánchezCIEMAT, Madrid, SpainDavid J. SchlegelLawrence Berkeley National Laboratory, Berkeley, CA USAHee‐Jong SeoDepartment of Physics & Astronomy, Ohio University, Athens, OH USADavid SprayberryNSF NOIRLab, Tucson, AZ USAG. TarléDepartment of Physics, University of Michigan, Ann Arbor, MI USAMichael WaltherExcellence Cluster ORIGINS, Garching, GermanyBenjamin A. WeaverNSF NOIRLab, Tucson, AZ USAPauline ZarroukLaboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Sorbonne Université, CNRS/IN2P3, Paris, FranceCheng ZhaoDepartment of Astronomy, Tsinghua University, Beijing, People's Republic of ChinaRongpu ZhouLawrence Berkeley National Laboratory, Berkeley, CA USAH. ZouNational Astronomical Observatories, Chinese Academy of Sciences, Beijing, People's Republic of China

Nature Astronomyjournal2025en

ABI

Abstract

Understanding whether cosmic acceleration arises from a cosmological constant or a dynamical component is a central goal of cosmology, and the Dark Energy Spectroscopic Instrument (DESI) enables stringent tests with high-precision distance measurements. Here we analyse measurements of baryon acoustic oscillations in DESI Data Release 1 and Data Release 2 and consider type Ia supernovae and a distance prior for the cosmic microwave background. With the larger statistical power and wider redshift coverage of Data Release 2, the preference for dynamical dark energy does not diminish relative to Data Release 1. Using both a shape-function reconstruction and non-parametric approaches with a Horndeski-motivated correlation prior, we find that the equation of state for dark energy w(z) varies with redshift. Baryon acoustic oscillation data alone yield modest constraints, but in combination with independent supernova compilations and the prior for the cosmic microwave background, they strengthen the evidence for dynamics. A Bayesian comparison of models shows moderate support for departures from Λ cold dark matter (ΛCDM) when several degrees of freedom in w(z) are allowed, corresponding to ~3σ tension with ΛCDM (and higher for some datasets). Despite methodological differences, our results are consistent with companion DESI papers, underscoring the complementarity of the approaches. Possible systematics remain under study; forthcoming DESI, Euclid and next-generation cosmic microwave background data will provide decisive tests. A complementary analysis of DESI DR2 distance measurements along with supernova and CMB data shows consistent, moderate evidence that dark energy changes over time rather than behaving as a simple cosmological constant.

Topics

Cosmology and Gravitation Theories Galaxies: Formation, Evolution, Phenomena Dark Matter and Cosmic Phenomena

Identifiers

DOI: 10.1038/s41550-025-02669-6

Citations and references

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