Speaker
Description
The Subaru Prime Focus Spectrograph (PFS) cosmology program will deliver redshifts for four million [OII] emission-line galaxies over 1200 deg² across 𝑧 = 0.6 to 𝑧 = 2.4, based on approximately 100 nights of observations. The program has two primary goals: (1) to rule out the inverted neutrino mass hierarchy by measuring Σ𝑚𝜈 < 0.1 eV at 95% CL, or to determine the total neutrino mass if Σ𝑚𝜈 > 0.1 eV, and (2) to test the standard ΛCDM paradigm by identifying time evolution in dark energy density or deviations from General Relativity (GR) on cosmological scales, or to confirm ΛCDM with unprecedented precision.
These goals will be achieved by measuring cosmological distances, the expansion rate, and the growth rate of matter density fluctuations with a few percent uncertainty across seven redshift bins. The program's wide redshift coverage enables robust internal consistency checks, while the high galaxy sample density allows extraction of small-scale clustering information. Additionally, synergy with Subaru Hyper Suprime-Cam (HSC) imaging data will enhance constraints on neutrino mass, dark energy, and modified gravity. Cross-correlations between 3D galaxy positions from PFS and weak lensing shear from HSC will improve parameter constraints and provide critical cross-checks, ensuring robust and transformative insights into the Universe.
