Impact of assuming flatness in the determination of neutrino properties from cosmological data

2011/12/31 by Aaron Smith, Maria Archidiacono, Asantha Cooray +4 · 14 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmic background radiation #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Curvature #Dark energy #Flatness (cosmology) #Flatness problem #Geometry #Metric expansion of space #Neutrino #Neutrino Physics Research #Omega #Particle physics #Physics #Quantum mechanics #Universe #astro-ph.CO

paper · pdf · doi:10.1103/physrevd.85.123521

published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 85(12) (American Physical Society) · 6 pages. 4 figures. Submitted to PRD

arxiv created 2012/06/01 · openalex publication_date 2012/06/14 · arxiv updated 2013/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Cosmological data have provided new constraints on the number of neutrino species and the neutrino mass. However, these constraints depend on assumptions related to the underlying cosmology. Since a correlation is expected between the number of effective neutrinos N_eff, the neutrino mass \ensuremath∑m_\ensuremathν, and the curvature of the universe \ensuremathΩ_k, it is useful to investigate the current constraints in the framework of a nonflat universe. In this paper we update the constraints on neutrino parameters by making use of the latest cosmic microwave background data from the Atacama Cosmology Telescope and South Pole Telescope experiments and consider the possibility of a universe with nonzero curvature. We first place new constraints on N_eff and \ensuremathΩ_k, with N_eff=4.03\ifmmode±\else\textpm\fi0.45 and 10³\ensuremathΩ_k=\ensuremath-4.46\ifmmode±\else\textpm\fi5.24. Thus, even when \ensuremathΩ_k is allowed to vary, N_eff=3 is still disfavored with 95% confidence. We then investigate the correlation between neutrino mass and curvature that shifts the 95% upper limit of \ensuremath∑m_\ensuremathν<0.45 eV to \ensuremath∑m_\ensuremathν<0.95 eV. Thus, the impact of assuming flatness in neutrino cosmology is significant and an essential consideration with future experiments.

Citations

• Cosmological constraints on a light nonthermal sterile neutrino
• Neutrino masses and the number of neutrino species from WMAP and 2dFGRS
• Limits on dark radiation, early dark energy, and relativistic degrees of freedom
• Massive neutrinos and cosmology
• A 3% SOLUTION: DETERMINATION OF THE HUBBLE CONSTANT WITH THEHUBBLE SPACE TELESCOPEAND WIDE FIELD CAMERA 3
• Neutrinos as cluster dark matter
• FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION

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• Dark energy from dark radiation in strongly coupled cosmologies with no fine tuning
• Dark radiation sterile neutrino candidates after Planck data
• Dark radiation and interacting scenarios