https://doi.org/10.1140/epjc/s10052-023-11820-4
Regular Article - Theoretical Physics
CMB polarization by the asymmetric template of scalar perturbations
1
Farhangian University, P.O. Box 11876-13311, Tehran, Iran
2
Iranian National Museum of Science and Technology (INMOST), PO BOX: 11369-14611, Tehran, Iran
3
School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran, Iran
4
Department of Physics, Shahid Beheshti University, 1983969411, Tehran, Iran
Received:
7
February
2023
Accepted:
9
July
2023
Published online:
23
July
2023
Inspired by a dipole asymmetric template for the CMB temperature map in the primordial scalar fluctuations observed by Planck at a large scale, we examine the contribution of a similar template for power asymmetry in modifying the linear polarization pattern of CMB. Replacing un-modulated temperature fluctuation with dipolar modulated one in time evolution equations somehow breaks linear perturbation in the various components of the CMB map. This non-linearity allows deflecting CMB polarization in patterns that contain divergence-free components. The explicit expressions for the angular power spectra of the electric and magnetic-type parities of linear polarization are derived in the form of the line of sight integral solutions. Our results demonstrate that the electric-type polarization is modified and the magnetic-type polarization would be produced. Such imprints depend on the linear and square of the asymmetric amplitude for E- and B-modes power spectra, respectively. For the observed dipole template, the value of B polarization spectrum at the large scale (
) is almost equivalent to the power spectrum obtained from Compton scattering in the presence of tensor perturbation with tensor to scalar ratio about 
.
© The Author(s) 2023
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