Presentation #202.03 in the session Cosmology — iPoster Session.
SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) is a NASA MIDEX Mission which will provide the first near infrared all-sky spectral survey. It recently passed its Critical Design Review and will be launched in 2025. I will give an overview on SPHEREx cosmology science aiming to measure the primordial non-Gaussianity parameter fNL, and what it can tell us about inflation. I will present updated forecasts on the ability of SPHEREx to constrain inflationary parameters using our near all-sky galaxy redshift survey. This forecast improves upon past published forecasts by including redshift space distortion effects, a multi-tracer analysis (involving 5 galaxy samples and 11 redshift bins up to z = 4.6), and higher-order bias parameters. I will also discuss various ways of reducing the bispectrum data vector dimension by studying how the fNL constraints are distributed.