Probing the Effective Number of Neutrino Species with Cosmic Microwave Background

Abstract

We discuss how much we can probe the effective number of neutrino species N_nu with cosmic microwave background alone. Using the data of WMAP, ACBAR, CBI and BOOMERANG experiments, we obtain a constraint on the effective number of neutrino species as 0.96< N_nu <7.94 at 95% C.L. for a power-law LCDM flat universe model. The limit is improved to be 1.39 < N_nu < 6.38 at 95% C.L. if we assume that the baryon density, N_nu and the helium abundance are related by the big bang nucleosynthesis theory. We also provide a forecast for the PLANCK experiment using a Markov chain Monte Carlo approach. In addition to constraining N_nu, we investigate how the big bang nucleosynthesis relation affects the estimation for these parameters and other cosmological parameters.

19 pages, 4 figures, 4 tables; update after WMAP 5-year results; accepted for publication in Phys. Rev. D

References in corpus (24)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• The Hubble Constant: A Summary of the HST Program for the Luminosity Calibration of Type Ia Supernovae by Means of Cepheids
• Probing cosmological parameters with the CMB: Forecasts from full Monte Carlo simulations
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP)Observations: Beam Maps and Window Functions
• Constraining The Early-Universe Baryon Density And Expansion Rate
• Observational bounds on the cosmic radiation density
• Using BBN in cosmological parameter extraction from CMB: a forecast for Planck
• Primordial helium recombination I: feedback, line transfer, and continuum opacity
• Cosmological hydrogen recombination: populations of the high level sub-states
• The Cosmic Microwave Background and the Ionization History of the Universe
• Neutrino masses and cosmic radiation density: Combined analysis
• Cosmology of neutrinos and extra light particles after WMAP3
• Constraint on the Effective Number of Neutrino Species from the WMAP and SDSS LRG Power Spectra
• Primordial helium recombination III: Thomson scattering, isotope shifts, and cumulative results
• Primordial Helium Abundance from CMB: a constraint from recent observations and a forecast
• Primordial helium recombination II: two-photon processes
• The Cosmic Neutrino Background and the Age of the Universe
• WMAP 5-year constraints on lepton asymmetry and radiation energy density: Implications for Planck
• Constraining Models of Neutrino Mass and Neutrino Interactions with the Planck Satellite
• Cosmological Constraint on the Effective Number of Neutrino Species

Cited by in corpus (17)

• The significance of the integrated Sachs-Wolfe effect revisited
• Sterile Neutrinos in Light of Recent Cosmological and Oscillation Data: a Multi-Flavor Scheme Approach
• Short-Baseline Electron Neutrino Disappearance, Tritium Beta Decay and Neutrinoless Double-Beta Decay
• Relic density of neutrinos with primordial asymmetries
• Detecting sterile neutrinos with KATRIN like experiments
• A theory of extra radiation in the Universe
• Higgs-Dilaton cosmology: Are there extra relativistic species?
• Electroweak Resonant Leptogenesis in the Singlet Majoron Model
• Observational constraints on cosmic neutrinos and dark energy revisited
• Constraints on neutrino masses from WMAP5 and BBN in the lepton asymmetric universe
• Constraining Light Gravitino Mass from Cosmic Microwave Background
• Big bang nucleosynthesis and early dark energy in light of the EMPRESS $Y_p$ results and the $H_0$ tension
• Variation of the fine structure constant in the light of recent helium abundance measurement
• Bounds on Very Weakly Interacting Sub-eV Particles (WISPs) from Cosmology and Astrophysics
• Effects of active-sterile neutrino mixing during primordial nucleosynthesis
• Constraints on cosmological parameters and CMB first acoustic peak in conformal Killing gravity
• The connection between cosmology and neutrino physics