Cosmological Parameter Determination from Counts of Galaxies

We study constraints that anticipated DEEP2 survey galaxy counts versus redshift data will place on cosmological model parameters in a model with space curvature and a constant cosmological constant Λ and in a spatially flat quintessence model with a time-variable Λ. These data will result in fairly tight constraints on these parameters. For example, if all other parameters of a spatially flat model with a constant Λ are known, the galaxy counts data should constrain the nonrelativistic matter density parameter Ω 0 to about 5% (10%, 1.5%) at 1 σ with neutral (worst case, best case) assumptions about data quality.