Reconstructing the CMB power spectrum

Abstract

We discuss a method for a model independent reconstruction of the CMB temperature fluctuation power spectrum on small and intermediate scales that is geared to individual experiments. The importance of off-diagonal correlations for determining the shape of the power spectrum is emphasized and some examples of a reconstruction method are given. By using this method to ``map'' the power spectrum on the scales to which they are sensitive several experiments could be combined to map out the full power spectrum, and test consistency of observed features. For example we find that the GUM scan of the 3rd flight of the MAX experiment prefers a positive slope to the power spectrum near $\ell\simeq160$, which provides weak evidence for the presence of a Doppler peak.