Expected dipole asymmetry in CMB polarization

Understand

We explore the hemispherical asymmetry predicted in cosmic microwave background polarization when there is an asymmetry in temperature anisotropies due to primordial perturbations.

• We consider the cases of asymmetries due to adiabatic and isocurvature modes, and tensor perturbations.
• We show that the asymmetry in the TE, EE and/or BB correlations can be substantially larger than those in the TT power spectrum in certain cases.
• The relative asymmetry in the different cross-correlations, as well as the angular scale dependence, can in principle distinguish between different origins for the asymmetry.