B-mode power spectrum of CMB via polarized Compton scattering

In this work, some evidences for existing an asymmetry in the density of left- and right-handed cosmic electrons (δL and δR respectively) in universe motivated us to calculate the dominated contribution of this asymmetry in the generation of the B-mode power spectrum. In the standard cosmological scenario, Compton scattering in the presence of scalar matter perturbation can not generate magnetic-like pattern in linear polarization CBl(S)=0 while in the case of polarized Compton scattering CBl(S)∝δL2. By adding up the power spectrum of the B-mode generated by the polarized Compton scattering to power spectra produced by weak lensing effects and Compton scattering in the presence of tensor perturbations, we show that there is a significant amplification in CBl in large scale l10−6, which can be observed in future experiments. Finally, we have shown that CBl(S) generated by polarized Compton scattering can suppress the tensor-to-scalar ratio (r-parameter) so that this contamination can be comparable to a primordial tensor-to-scalar ratio spatially for δL>10−5.