J-PAS and PFS surveys in the era of dark energy and neutrino mass measurements

TL;DR

This paper forecasts the combined cosmological constraints of J-PAS and PFS surveys, showing their potential to improve measurements of neutrino mass and dark energy properties when combined with CMB data.

Contribution

It presents Fisher-matrix forecasts demonstrating how J-PAS and PFS surveys, combined with CMB data, can significantly enhance constraints on neutrino mass hierarchy and dark energy evolution.

Findings

Expected neutrino mass uncertainty of 0.017 eV with combined data.

Potential to disfavour inverted neutrino hierarchy at 2.34 sigma.

Strong constraints on dark energy equation of state evolution.

Abstract

Fisher-matrix forecasts are presented for the cosmological surveys of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) and the Subaru Prime Focus Spectrograph (PFS). The wide, low-redshift coverage of J-PAS and the high-density, high-redshift mapping of PFS are strongly complementary: combining the two reduces marginalized uncertainties on all primary parameters compared with either survey individually. Adding the joint J-PAS+PFS data to next-generation CMB measurements from the Simons Observatory (SO) and \textsc{LiteBird} yields an expected precision of $\sigma(\sum m_\nu)=0.017\,$eV in the $\Lambda$CDM$+\sum m_\nu+N_{\rm eff}$ framework, sufficient to disfavour the inverted neutrino hierarchy at $2.34\,\sigma$ if the true mass sum equals the normal-ordering minimum. Motivated by recent DESI results, we also forecast within a $w_0w_a$CDM$+\sum m_\nu+N_{\rm eff}$ cosmology, adopting the DESI\,DR2 best-fit values ($w_0=-0.758$, $w_a=-0.82$) as fiducial. The combination CMB+J-PAS+PFS then delivers $\sigma(w_0)=0.044$ and $\sigma(w_a)=0.18$, corresponding to a $5.1\,\sigma$ preference for a time-varying dark-energy equation of state. These findings show that J-PAS and PFS, especially when coupled with Stage-IV CMB observations, will provide competitive tests of neutrino physics and the dynamics of cosmic acceleration.