Testing physical models for dipolar asymmetry with CMB polarization

Understand

The cosmic microwave background (CMB) temperature anisotropies exhibit a large-scale dipolar power asymmetry.

• To determine whether this is due to a real, physical modulation or is simply a large statistical fluctuation requires the measurement of new modes.
• Here we forecast how well CMB polarization data from \Planck\ and future experiments will be able to confirm or constrain physical models for modulation.
• Fitting several such models to the \Planck\ temperature data allows us to provide predictions for polarization asymmetry.