Article

The Atacama Cosmology Telescope: DR6 constraints on extended cosmological models

Erminia CalabreseSchool of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA, U.KJ. Colin HillDepartment of Physics, Columbia University, New York, NY 10027, U.S.AHidde T. JenseSchool of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA, U.KAdrien La PostaDepartment of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, U.KIrene Abril-CabezasDAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 OWA, U.KGraeme E. AddisonDept. of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686, U.S.AP. A. R. AdeSchool of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA, U.KSimone AiolaFlatiron Institute, 162 5th Avenue, New York, NY 10010, U.S.ATommy AlfordDepartment of Physics, University of Chicago, Chicago, IL 60637, U.S.ADavid AlonsoDepartment of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, U.KM. AmiriDepartment of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4, CanadaRui AnDepartment of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, U.S.AZachary AtkinsJoseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544, U.S.AJason E. AustermannEleonora BarbavaraPhysics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyNicola BarbieriDipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, I-44122 Ferrara, ItalyNicholas BattagliaDepartment of Astronomy, Cornell University, Ithaca, NY 14853, U.S.AE. S. BattistelliPhysics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyJames A. BeallRachel BeanDepartment of Astronomy, Cornell University, Ithaca, NY 14853, U.S.AAli BeheshtiDepartment of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, U.S.ABenjamin BeringueUniversite Paris Cite, CNRS, Astroparticule et Cosmologie, F-75013 Paris, FranceTanay BhandarkarDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.AEmily BiermannLos Alamos National Laboratory, Bikini Atoll Rd, Los Alamos, NM, 87545, U.S.ABoris BollietDepartment of Physics, Madingley Road, Cambridge CB3 0HA, U.KJ. Richard BondCanadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8, CanadaValentina CapalboPhysics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyFelipe CarreroInstituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, ChileShi-Fan ChenInstitute for Advanced Study, 1 Einstein Dr, Princeton, NJ 08540, U.S.AGrace E. ChesmoreDepartment of Physics, University of Chicago, Chicago, IL 60637, U.S.AHsiao-mei ChoNIST Quantum Sensors Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305, U.S.ASteve K. ChoiDepartment of Physics and Astronomy, University of California, Riverside, CA 92521, U.S.ASusan E. ClarkDepartment of Physics, Stanford University, Stanford, CA, U.S.ANicholas F. CothardNASA/Goddard Space Flight Center, Greenbelt, MD 20771, U.S.AKevin CoughlinDepartment of Physics, University of Chicago, Chicago, IL 60637, U.S.AWilliam R. CoultonDAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 OWA, U.KDevin CrichtonInstitute for Particle Physics and Astrophysics, ETH Zurich, 8092 Zurich, SwitzerlandKevin T. CrowleyDepartment of Astronomy and Astrophysics, University of California San Diego, La Jolla, CA 92093, U.S.AOmar DarwishUniversité de Genève, Département de Physique Théorique et CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4, SwitzerlandMark J. DevlinDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.ASimon DickerDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.ACody J. DuellDepartment of Physics, Cornell University, Ithaca, NY 14853, U.S.AShannon M. DuffAdriaan J. DuivenvoordenMax-Planck-Institut fur Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, GermanyJo DunkleyDepartment of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, U.S.ARolando DünnerInstituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, ChileCarmen Embil-VillagraDAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 OWA, U.KMax FankhanelCamino a Toconao 145-A, Ayllu de Solor, San Pedro de Atacama, ChileGerrit S. FarrenBerkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720, U.S.AS. FerraroBerkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720, U.S.AA. FosterJoseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544, U.S.ARodrigo FreundtDepartment of Astronomy, Cornell University, Ithaca, NY 14853, U.S.ABrittany FuziaDepartment of Physics, Florida State University, Tallahassee FL 32306, U.S.APatricio A. GallardoDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.AX. GarridoUniversité Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, FranceM. GerbinoIstituto Nazionale di Fisica Nucleare (INFN), Sezione di Ferrara, Via G. Saragat 1, I-44122 Ferrara, ItalySerena GiardielloSchool of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA, U.KAjay GillDepartment of Aeronautics & Astronautics, Massachusetts Institute of Technology, 77 Mass. Avenue, Cambridge, MA 02139, U.S.AJahmour J. GivansDepartment of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, U.S.AVera GluscevicDepartment of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, U.S.ASamuel GoldsteinDepartment of Physics, Columbia University, New York, NY 10027, U.S.AJoseph E. GolecDepartment of Physics, University of Chicago, Chicago, IL 60637, U.S.AYulin GongDepartment of Astronomy, Cornell University, Ithaca, NY 14853, U.S.AYilun GuanDunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON M5S 3H4, CanadaM. HalpernDepartment of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4, CanadaI. HarrisonSchool of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA, U.KMatthew HasselfieldFlatiron Institute, 162 5th Avenue, New York, NY 10010, U.S.AAdam HeDepartment of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, U.S.AErin HealyDepartment of Physics, University of Chicago, Chicago, IL 60637, U.S.AShawn HendersonSLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park, California 94025, U.S.ABrandon S. HensleyJet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, U.S.ACarlos Hervías-CaimapoInstituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, ChileG. C. HiltonMatt HiltonAstrophysics Research Centre, School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban 4001, South AfricaAdam D. HincksDavid A. Dunlap Dept of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto ON, M5S 3H4, CanadaRenée HložekDavid A. Dunlap Dept of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto ON, M5S 3H4, CanadaShuay-Pwu Patty HoJoseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544, U.S.AJ. C. HoodDepartment of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637, U.S.AErika HorneckerDavid A. Dunlap Dept of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto ON, M5S 3H4, CanadaZachary B. HuberDepartment of Physics, Cornell University, Ithaca, NY 14853, U.S.AJohannes HubmayrK. M. HuffenbergerMitchell Institute for Fundamental Physics & Astronomy and Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, U.S.AJohn P. HughesDepartment of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019, U.S.AMargaret IkapeDavid A. Dunlap Dept of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto ON, M5S 3H4, CanadaK. D. IrwinDepartment of Physics, Stanford University, Stanford, CA, U.S.AGiovanni IsopiPhysics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyNeha JoshiDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.ABen KellerDepartment of Physics, Cornell University, Ithaca, NY 14853, U.S.AJoshua KimDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.AKenda KnowlesCentre for Radio Astronomy Techniques and Technologies, Department of Physics and Electronics, Rhodes University, P.O. Box 94, Makhanda 6140, South AfricaBrian J. KoopmanDepartment of Physics, Yale University, 217 Prospect St, New Haven, CT 06511, U.S.AArthur KosowskyDepartment of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, U.S.ADarby KramerSchool of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, U.S.AAleksandra KusiakInstitute of Astronomy, Madingley Road, Cambridge CB3 0HA, U.KAlex LaguëDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.AVictoria LakeyDepartment of Chemistry and Physics, Lincoln University, PA 19352, U.S.AM. LattanziIstituto Nazionale di Fisica Nucleare (INFN), Sezione di Ferrara, Via G. Saragat 1, I-44122 Ferrara, ItalyEunseong LeeDepartment of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.AYaqiong LiDepartment of Physics, Cornell University, Ithaca, NY 14853, U.S.AZack LiBerkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720, U.S.A

2025en

ABI

Abstract

Abstract We use new cosmic microwave background (CMB) primary temperature and polarization anisotropy measurements from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) to test foundational assumptions of the standard cosmological model, ΛCDM, and set constraints on extensions to it. We derive constraints from the ACT DR6 power spectra alone, as well as in combination with legacy data from the Planck mission. To break geometric degeneracies, we include ACT and Planck CMB lensing data and baryon acoustic oscillation data from DESI Year-1. To test the dependence of our results on non-ACT data, we also explore combinations replacing Planck with WMAP and DESI with BOSS, and further add supernovae measurements from Pantheon+ for models that affect the late-time expansion history. We verify the near-scale-invariance (running of the spectral index dn s / d ln k = 0.0062 ± 0.0052) and adiabaticity of the primordial perturbations. Neutrino properties are consistent with Standard Model predictions: we find no evidence for new light, relativistic species that are free-streaming ( N eff = 2.86 ± 0.13, which combined with astrophysical measurements of primordial helium and deuterium abundances becomes N eff = 2.89 ± 0.11), for non-zero neutrino masses (∑ m ν < 0.089 eV at 95% CL), or for neutrino self-interactions. We also find no evidence for self-interacting dark radiation ( N idr < 0.134), or for early-universe variation of fundamental constants, including the fine-structure constant ( α EM / α EM,0 = 1.0043 ± 0.0017) and the electron mass ( m e / m e,0 = 1.0063 ± 0.0056). Our data are consistent with standard big bang nucleosynthesis (we find Y p = 0.2312 ± 0.0092), the COBE/FIRAS -inferred CMB temperature (we find T CMB = 2.698 ± 0.016 K), a dark matter component that is collisionless and with only a small fraction allowed as axion-like particles, a cosmological constant ( w = -0.986 ± 0.025), and the late-time growth rate predicted by general relativity ( γ = 0.663 ± 0.052). We find no statistically significant preference for a departure from the baseline ΛCDM model. In fits to models invoking early dark energy, primordial magnetic fields, or an arbitrary modified recombination history, we find H 0 = 69.9 +0.8 -1.5 , 69.1 ± 0.5, or 69.6 ± 1.0 km/s/Mpc, respectively; using BOSS instead of DESI BAO data reduces the central values of these constraints by 1–1.5 km/s/Mpc while only slightly increasing the error bars. In general, models introduced to increase the Hubble constant or to decrease the amplitude of density fluctuations inferred from the primary CMB are not favored over ΛCDM by our data.

Identifiers

DOI: 10.1088/1475-7516/2025/11/063

Citations and references

Cited by 20 references

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