A perceptron based ILC method to obtain accurate CMB B-mode angular power spectrum

Abstract: Observations of the Cosmic Microwave Background (CMB) radiation have made significant contributions to our understanding of cosmology. While temperature observations of the CMB have greatly advanced our knowledge, the next frontier lies in detecting the elusive B-modes and obtaining precise reconstructions of the CMB's polarized signal in general. In anticipation of proposed and upcoming CMB polarization missions, this study introduces a novel method for accurately determining the angular power spectrum of CMB B-modes. We have developed a Neural Network-based approach to enhance the performance of the Internal Linear Combination (ILC) technique. Our method is applied to the frequency channels of the proposed ECHO (Exploring Cosmic History and Origins) mission and its performance is rigorously assessed. Our findings demonstrate the method's efficiency in achieving precise reconstructions of CMB B-mode angular power spectra, with errors constrained primarily by cosmic variance.