Do observations prove that cosmological neutrinos are thermally distributed?
arXiv:astro-ph/0502465 · doi:10.1103/PhysRevD.71.123501
Abstract
It is usually assumed that relic neutrinos possess a Fermi-Dirac distribution, acquired during thermal equilibrium in the Early Universe. However, various mechanisms could introduce strong distortions in this distribution. We perform a Bayesian likelihood analysis including the first moments of the three active neutrino distributions as free parameters, and show that current cosmological observations of light element abundances, Cosmic Microwave Background (CMB) anisotropies and Large Scale Structures (LSS) are compatible with very large deviations from the standard picture. We also calculate the bounds on non-thermal distortions which can be expected from future observations, and stress that CMB and LSS data alone will not be sensitive enough in order to distinguish between non-thermal distortions in the neutrino sector and extra relativistic degrees of freedom. This degeneracy could be removed by additional constraints from primordial nucleosynthesis or independent neutrino mass scale measurements.
arXiv comment12 pages, 4 figures
References in corpus (51)
- First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
- First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
- Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
- Cosmological parameters from CMB and other data: a Monte-Carlo approach
- Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
- A Line of Sight Approach to Cosmic Microwave Background Anisotropies
- The 3D power spectrum of galaxies from the SDSS
- The 2dF Galaxy Redshift Survey: The power spectrum and the matter content of the universe
- A measurement of the cosmological mass density from clustering in the 2dF Galaxy Redshift Survey
- Mass Reconstruction with CMB Polarization
- Neutrinos in cosmology
- First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Parameter Estimation Methodology
- What is the lowest possible reheating temperature?
- Double Beta Decay
- Weighing Neutrinos with Galaxy Surveys
- The cosmological baryon density from the deuterium to hydrogen ratio towards QSO absorption systems: D/H towards Q1243+3047
- Cosmological bounds on neutrino degeneracy improved by flavor oscillations
- High Resolution Observations of the CMB Power Spectrum with ACBAR
- Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra
- Extended Mosaic Observations with the Cosmic Background Imager
- Systematic effects and a new determination of the primordial abundance of 4He and dY/dZ from observations of blue compact galaxies
- Primordial Nucleosynthesis for the New Cosmology: Determining Uncertainties and Examining Concordance
- A precision calculation of the effective number of cosmological neutrinos
- The Anisotropy of the Microwave Background to l = 3500: Mosaic Observations with the Cosmic Background Imager
- Nuclear Reaction Network for Primordial Nucleosynthesis: a detailed analysis of rates, uncertainties and light nuclei yields
- A Realistic Determination of the Error on the Primordial Helium Abundance: Steps Toward Non-Parametric Nebular Helium Abundances
- Nonequilibrium Corrections to the Spectra of Massless Neutrinos in the Early Universe
- Cosmological Parameters from Cosmic Background Imager Observations and Comparisons with BOOMERANG, DASI, and MAXIMA
- Stringent Constraints on Cosmological Neutrino-Antineutrino Asymmetries from Synchronized Flavor Transformation
- Effective number of neutrinos and baryon asymmetry from BBN and WMAP
- Present status of primordial nucleosynthesis after WMAP: results from a new BBN code
- Estimates of Cosmological Parameters Using the CMB Angular Power Spectrum of ACBAR
- Observables sensitive to absolute neutrino masses: Constraints and correlations from world neutrino data
- Constraining neutrino physics with BBN and CMBR
- MeV-mass dark matter and primordial nucleosynthesis
- Probing neutrino masses with future galaxy redshift surveys
- Current cosmological bounds on neutrino masses and relativistic relics
- On the Evolution of Helium in Blue Compact Galaxies
- Cosmological mass limits on neutrinos, axions, and other light particles
- Cosmological implications of a Relic Neutrino Asymmetry
- The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies
- Evolution of cosmological dark matter perturbations
- Cosmological parameter estimation using Very Small Array data out to l=1500
- Bayesian model selection and isocurvature perturbations
- Measuring the cosmological background of relativistic particles with WMAP
- Constraining the helium abundance with CMB
- Standard Model Neutrinos as Warm Dark Matter
- Improved Treatment of Cosmic Microwave Background Fluctuations Induced by a Late-decaying Massive Neutrino
- Spin-Statistics Connexion, Neutrinos, and Big Bang Nucleosynthesis
- Probing neutrino decays with the cosmic microwave background
- Late-time Entropy Production from Scalar Decay and Relic Neutrino Temperature
Cited by in corpus (39)
- Primordial Nucleosynthesis: from precision cosmology to fundamental physics
- The Cosmic Linear Anisotropy Solving System (CLASS) IV: Efficient implementation of non-cold relics
- Precision Early Universe Thermodynamics made simple: and Neutrino Decoupling in the Standard Model and beyond
- Light sterile neutrinos
- Cosmological Signatures of Interacting Neutrinos
- Primordial Neutrinos
- Dark Radiation Emerging After Big Bang Nucleosynthesis?
- Effects of non-standard neutrino-electron interactions on relic neutrino decoupling
- Long Range Interactions in Cosmology: Implications for Neutrinos
- Squeezing the window on isocurvature modes with the Lyman-alpha forest
- Constraints on secret neutrino interactions after Planck
- Cosmological constraints on a light non-thermal sterile neutrino
- Dark Radiation or Warm Dark Matter from long lived particle decays in the light of Planck
- How to relax the cosmological neutrino mass bound
- Cosmic Neutrino Background Detection in Large-Neutrino-Mass Cosmologies
- What can CMB observations tell us about the neutrino distribution function?
- CosmoBit: A GAMBIT module for computing cosmological observables and likelihoods
- Origin of Delta N_eff as a Result of an Interaction between Dark Radiation and Dark Matter
- Neutrino statistics and big bang nucleosynthesis
- Is it possible to tell the difference between fermionic and bosonic hot dark matter?
- Big Bang Nucleosynthesis with Independent Neutrino Distribution Functions
- Neutrino mass tension or suppressed growth rate of matter perturbations?
- Was Entropy Conserved between BBN and Recombination?
- Nuclear weak interaction rates in primordial nucleosynthesis
- Large neutrino mass in cosmology and keV sterile neutrino dark matter from a dark sector
- Non-thermal Hot Dark Matter from Inflaton/Moduli Decay: The Momentum Distribution and Relaxing the Cosmological Mass Bound
- Non-thermal neutrino-like hot dark matter in light of the tension
- Revisiting signatures of thermal axions in nonstandard cosmologies
- Signatures of Light Massive Relics on nonlinear structure formation
- Daughters mimic sterile neutrinos (almost!) perfectly
- CMB anisotropies and linear matter power spectrum in models with non-thermal neutrinos and primordial magnetic fields
- Neutrino decays as a natural explanation of the neutrino mass tension
- Scale and redshift dependent limits on cosmic neutrino properties
- Primordial neutrinos fade to gray: constraints from cosmological observables
- Fifty shades of grayness: parametrizations of spectral distortions and applications in cosmology
- Exploring the cosmological degeneracy between decaying dark matter model and viscous CDM
- Forecasting Constraints on Non-Thermal Light Massive Relics from Future CMB Experiments (CMB-S4/Simons Observatory)
- Constraints on the velocity dispersion of Dark Matter from Cosmology and new bounds on scattering from the Cosmic Dawn
- Non Thermal Features in the Cosmic Neutrino Background