IMPRINT OF OMEGA ON THE COSMIC MICROWAVE BACKGROUND

We investigate the dependence of large-angular-scale cosmic microwave background anisotropies on various initial conditions, including both adiabatic and isocurvature perturbations and the initial power-law ind ex n, in a variety of low-OMEGA cosmological models. LAMBDA-dominated flat models, inflationary open adiabatic models, with n(eff) < 1, and open isocurvature models, with n(eff) congruent-to 2, are significantl y constrained.