Measuring neutrino mass imprinted on the anisotropic galaxy clustering

TL;DR

This paper analyzes anisotropic galaxy clustering data from BOSS DR11 to constrain the sum of neutrino masses, proposing a new method that leverages the deformation of the power spectrum shape at later epochs, achieving a tentative detection of neutrino mass.

Contribution

It introduces a novel approach to measure neutrino mass by examining the shape deformation of the power spectrum in redshift space, combining this with distance and growth measurements for improved constraints.

Findings

Neutrino mass estimated as 0.19 eV with uncertainties

Method effectively separates neutrino effects from other cosmological parameters

Constraints are consistent with a non-zero neutrino mass at 68% confidence

Abstract

The anisotropic galaxy clustering of large scale structure observed by the Baryon Oscillation Spectroscopic Survey Data Release 11 is analyzed to probe the sum of neutrino mass in the small $m_\nu < 1eV$ limit in which the early broadband shape determined before the last scattering surface is immune from the variation of $m_\nu$. The signature of $m_\nu$ is imprinted on the altered shape of the power spectrum at later epoch, which provides an opportunity to access the non--trivial $m_\nu$ through the measured anisotropic correlation function in redshift space (hereafter RSD instead of Redshift Space Distortion). The non--linear RSD corrections with massive neutrinos in the quasi linear regime are approximately estimated using one-loop order terms computed by tomographic linear solutions. We suggest a new approach to probe $m_\nu$ simultaneously with all other distance measures and coherent growth functions, exploiting this deformation of the early broadband shape of the spectrum at later epoch. If the origin of cosmic acceleration is unknown, $m_\nu$ is poorly determined after marginalising over all other observables. However, we find that the measured distances and coherent growth functions are minimally affected by the presence of mild neutrino mass. Although the standard model of cosmic acceleration is assumed to be the cosmological constant, the constraint on $m_\nu$ is little improved. Interestingly, the measured CMB distance to the last scattering surface sharply slices the degeneracy between the matter content and $m_\nu$, and the hidden $m_\nu$ is excavated to be $m_\nu=0.19^{+0.28}_{-0.17} eV$ which is different from massless neutrino more than 68% confidence.