Large Angle Cmb Anisotropy in an Open Universe in the One-bubble Innationary Scenario

We consider an alternative scenario of innation which can account for a spatially open universe. It is similar to the old innation in which the bubble nucleation occurs in the sea of false vacuum, but diiers from it in that the second slow rollover innation occurs inside a nucleated bubble. Hence our observable universe is entirely contained in one nucleated bubble. The signiicance of the scenario is that apart from a variance due to model parameters it gives us a deenite prediction on the spectrum of the primordial density perturbations, hence is observationally testable. Here we investigate the spectrum of CMB anisotropies on large angular scales. We nd that the contribution from peculiar modes which never appear in the usual harmonic analysis is signiicant in the case 0 < 0:1.