Uncorrelated measurements of the CMB power spectrum

Abstract

We describe how to compute estimates of the power spectrum C_l from Cosmic Microwave Background (CMB) maps that not only retain all the cosmological information, but also have uncorrelated error bars and well-behaved window functions. We apply this technique to the 4-year COBE/DMR data, and tabulate eight uncorrelated band-powers.

Figures (2)

• Figure 1: The $\ell_*=10$ window functions for the three methods discussed, corresponding to using the original ${\bf y}$, Cholesky decomposing the Fisher matrix and taking its square root, respectively.
• Figure 2: The power spectrum observed by COBE/DMR alone (left) and binned into 8 bands and compared with other experiments (right).