Abstract Details

Name: Archana Sangwan
Affiliation: Indian Institute of Technology Bombay
Conference ID: ASI2020_316
Title : Primordial magnetic fields and B-mode polarization in CMB
Authors and Co-Authors : Archana Sangwan and S. Shankaranarayanan
Abstract Type : Oral
Abstract Category : General Relativity and Cosmology
Abstract : The existence of the primordial magnetic field (PMF) in the early Universe affects the evolution of cosmological perturbations and potentially leaves an imprint on CMB anisotropies. We look at the effects of the stochastic magnetic field of nano-Gauss strength on the Polarization of the CMB. The effect of magnetic fields is more evident in lensed B-mode polarization than in case of temperature or E-mode spectra. We focus on the B-mode power spectrum, where there is a significant suppression of power at l > 200 in the presence of primordial magnetic fields. We use the BICEP2 data of B-mode polarization and perform the likelihood analysis. We find that the observations are in agreement (within 3σ limit) with nonzero PMF cases, and hence, their presence can not be ruled out. Until now, the only available data of the B-mode is up to l < 300, and thus we can not put any bound on PMF. We provide a detailed analysis of the B-mode polarization of the CMB with primordial magnetic fields and possible implications for future CMB observations.