Analysis of CMB maps with 2D wavelets

We consider the 2D wavelet transform with two scales to study sky maps of t emperature anisotropies in the cosmic microwave background radiation (CMB). We apply this technique to simulated maps of small sky patches of size 12. 8 degrees x 12.8 degrees and 1.5' x 1.5' pixels, The relation to the standa rd approach, based on the C(l)(')s, is established through the introduction of the scalogram. We consider temperature fluctuations derived from standa rd, open and flat-Lambda Cold Dark Matter (CDM) models. We analyze CMB anis otropies maps plus uncorrelated Gaussian noise (uniform and non-uniform) at different S/N levels. We explore in detail the denoising of such maps and compare the results with other techniques already proposed in the literatur e. Wavelet methods provide a good reconstruction of the image and power spe ctrum, Moreover. they are faster than previously proposed methods.