Constraints on Cosmological Parameters from Existing CMB Data

Abstract

We use current cosmic microwave background data to constrain cosmological parameters. The results are presented as confidence regions in the ($\Omega$--$H_o$) -- plane for both open and flat geometries, and are based on a ${\chi }^2$ minimization to the power spectrum. Although such an approach does not strictly apply to power spectrum estimates, the results should nonetheless be indicative. We find that purely open, low--$\Omega$ models are strongly disfavored, due to the position of the ``Doppler Peak'' at high $l$; flat models are less strongly constrained. The parameter space explored is the largest to date, covering $\Omega$, $H_o$, $n$, $Q$ and ${\Omega }_B{h}^2$.

To appear in "Fundamental Parameters in Cosmology", proceedings of the Rencontres de Moriond 1998