Determining Cosmological Parameters from the Microwave Background

Abstract

Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately experiments of this type will measure the basic cosmological parameters $\Omega$ (the total density of the Universe), $\Omega_b$ (the baryon density), $h$ (the Hubble constant), and $\Lambda$ (the cosmological constant). The proposed experiments are capable of measuring these parameters at the few-percent level. We briefly discuss the generality of these estimates and complications arising in actual data analysis.