Probing statistical isotropy of cosmological radio sources using SKA
  There currently exist many observations which are not consistent with the
cosmological principle. We review these observations with a particular emphasis
on those relevant for Square Kilometre Array (SKA). In particular, several
different data sets indicate a preferred direction pointing approximately
towards the Virgo cluster. We also observe a hemispherical anisotropy in the
Cosmic Microwave Background Radiation (CMBR) temperature fluctuations. Although
these inconsistencies may be attributed to systematic effects, there remains
the possibility that they indicate new physics and various theories have been
proposed to explain them. One possibility, which we discuss in this review, is
the generation of perturbation modes during the early pre-inflationary epoch,
when the Universe may not obey the cosmological principle. Better measurements
will provide better constraints on these theories. In particular, we propose
measurement of the dipole in number counts, sky brightness, polarized flux and
polarization orientations of radio sources. We also suggest test of alignment
of linear polarizations of sources as a function of their relative separation.
Finally we propose measurement of hemispherical anisotropy or equivalently
dipole modulation in radio sources.
