Towards testing CMB anomalies using the kinetic and polarized Sunyaev
  Zel'dovich effects
  Measurements of the Cosmic Microwave Background (CMB) temperature
anisotropies on large angular scales have uncovered a number of anomalous
features of marginal statistical significance, such as a hemispherical power
asymmetry, lack of power on large angular scales, and features in the power
spectrum. Because the primary CMB temperature has been measured at the cosmic
variance limit, determining if these anomalies are hints of new physics as
opposed to foregrounds, systematics, or simply statistical flukes, requires new
observables. In this paper, we highlight the potential contribution that future
measurements of the kinetic Sunyaev-Zel'dovich effect (kSZ) and the polarized
Sunyaev Zel'dovich effect (pSZ) could make in determining the physical nature
of several CMB anomalies. The kSZ and pSZ effects, temperature and polarization
anisotropies induced by scattering from free electrons in the reionized
Universe, are the dominant blackbody contribution to the CMB on small angular
scales. Using the technique of SZ tomography, measurements of kSZ and pSZ
effects can be combined with galaxy surveys to reconstruct the remote CMB
dipole and quadrupole fields, providing a 3-dimensional probe of large scale
modes inside our Hubble volume. Building on previous work, we forecast the
additional constraining power that these observables might offer for a
representative set of anomaly models. We find that the remote CMB dipole and
quadrupole contain a similar amount of information on anomaly models as the
primary CMB polarization. The information from CMB temperature, polarization,
and the remote dipole and quadrupole fields is complementary, and the full set
of observables can improve constraints on anomaly models by a factor of $\sim
2-4$ using next-generation CMB experiments and galaxy surveys. This could be
sufficient to definitively establish the physical origin of several CMB
anomalies.
