A Pixel Space Method for Testing Dipole Modulation in the CMB
  Polarization
  We introduce a pixel space method to detect dipole modulation or
hemispherical power asymmetry in the cosmic microwave background (CMB)
polarization. The method relies on the use of squared total polarized flux
whose ensemble average picks up a dipole due to the dipole modulation in the
CMB polarization. The method is useful since it can be applied easily to
partial sky. We define several statistics to characterize the amplitude of the
detected signal. By simulations we show that the method can be used to reliably
extract the signal at 2.7$\sigma$ level or higher in future CORE-like missions,
assuming that the signal is present in the CMB polarization at the level
detected by the Planck mission in the CMB temperature. An application of the
method to the 2018 Planck data does not detect a significant effect, when
taking into account the presence of correlated detector noise and residual
systematics in data. Using the FFP10 we find the presence of a very strong bias
which might be masking any real effect.
