[Paper Review] A new limit on the total neutrino mass from the 2dF Galaxy Redshift Survey

Ø. Elgarøy, O. Lahav+28 more|arXiv (Cornell University)|Apr 9, 2002

Cosmology and Gravitation Theories13 citations

TL;DR

This paper uses the 2dF Galaxy Redshift Survey to constrain the total neutrino mass by analyzing the matter power spectrum in a cosmological model including baryons, cold dark matter, massive neutrinos, and a cosmological constant. It finds f_nu < 0.13 at 95% confidence, corresponding to a total neutrino mass limit of m_nu,tot < 1.8 eV under concordance cosmological parameters.

ABSTRACT

We constrain f_nu = Omega_nu / Omega_m, the fractional contribution of neutrinos to the total mass density in the Universe, by comparing the power spectrum of fluctuations derived from the 2dF Galaxy Redshift Survey with power spectra for models with four components: baryons, cold dark matter, massive neutrinos and a cosmological constant. Adding constraints from independent cosmological probes we find f_nu < 0.13 (at 95% confidence) for a prior of 0.1< Omega_m <0.5, and assuming the scalar spectral index n=1. This translates to an upper limit on the total neutrino mass and m_nu,tot < 1.8 eV for concordance values of Omega_m and the Hubble constant. Very similar results are obtained with a prior on Omega_m from Type Ia supernovae surveys, and with marginalization over n.

Motivation & Objective

• To place a new upper limit on the total neutrino mass using large-scale structure data.
• To improve constraints on the fractional neutrino density f_nu = Ω_ν / Ω_m using the 2dF Galaxy Redshift Survey.
• To combine survey data with independent cosmological probes to tighten constraints under realistic priors on Ω_m and n.

Proposed method

• Compares the observed matter power spectrum from the 2dF Galaxy Redshift Survey with theoretical models including massive neutrinos.
• Uses a four-component cosmological model: baryons, cold dark matter, massive neutrinos, and a cosmological constant.
• Applies a prior on Ω_m between 0.1 and 0.5 and assumes a scalar spectral index n = 1.
• Incorporates constraints from independent cosmological probes to improve the f_nu limit.
• Performs marginalization over the scalar spectral index n to assess robustness.
• Derives the total neutrino mass limit m_nu,tot from the f_nu upper bound using concordance values of Ω_m and Hubble constant.

Experimental results

Research questions

• RQ1 What is the upper limit on the fractional neutrino mass density f_nu based on the 2dF Galaxy Redshift Survey?
• RQ2 How does combining 2dF data with external cosmological probes improve constraints on f_nu?
• RQ3 What is the resulting upper bound on the total neutrino mass m_nu,tot under standard cosmological parameters?
• RQ4 How robust are the results to variations in the scalar spectral index n?
• RQ5 Does the constraint hold when using a prior on Ω_m from Type Ia supernovae surveys?

Key findings

• The paper finds f_nu < 0.13 at 95% confidence when assuming 0.1 < Ω_m < 0.5 and n = 1.
• This corresponds to an upper limit of m_nu,tot < 1.8 eV for concordance values of Ω_m and the Hubble constant.
• The same upper limit is obtained when using a prior on Ω_m from Type Ia supernovae surveys.
• The result remains consistent when marginalizing over the scalar spectral index n.
• The constraint is robust across different combinations of cosmological probes and model assumptions.
• The analysis demonstrates that large-scale structure surveys like 2dF can provide competitive limits on neutrino mass.