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

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 $\ddot{I}ƒ(\sum m_{\hat{I}}½)=0.017$eV in the $\hat{I}›$CDM$+\sum m_{\hat{I}}½+N_{\mathrm{eff}}$ framework, sufficient to disfavour the inverted neutrino hierarchy at $2.34\ddot{I}ƒ$ if the true mass sum equals the normal-ordering minimum. Motivated by recent DESI results, we also forecast within a $w_0{w}_a$CDM$+\sum m_{\hat{I}}½+N_{\mathrm{eff}}$ 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 $\ddot{I}ƒ(w_0)=0.044$ and $\ddot{I}ƒ(w_a)=0.18$, corresponding to a $5.1\ddot{I}ƒ$ 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.

18 pages, 11 figures, 6 tables; published in ApJ; Forecast code is publicly available at https://github.com/Striker-png/NeutrinoForecast_J-PAS_PFS