Influence of the Local Void on measurements of the clustering dipole
  In measurements of the clustering dipole from all-sky surveys, an important
problem is the lack of information about galaxy distribution in the so-called
Zone of Avoidance (ZoA). The existence of the Local Void (LV) has a systematic
effect on these measurements. If the ZoA is randomly filled with mock galaxies,
then the calculated acceleration of the Local Group of galaxies (LG) has a
spurious component, resulting from the lack of real galaxies in the
intersection of the LV with the ZoA. This component affects both the
misalignment angle between the clustering dipole and the CMB dipole, and the
inferred value of mean matter density Omega_m. We calculate the amplitude of
the spurious acceleration acting on the LG due to the LV. Its value depends on
the geometry and size of the LV, as well as on its density contrast. However,
under the simplest assumption of the LV being spherical and completely empty,
within the linear theory this amplitude amounts only to about 45 km/s in units
of velocity. The resulting change in the misalignment angle is smaller than 1
degree, and the fractional change in the deduced value of Omega_m is about 5%.
Accounting for observationally indicated elongation of the LV and maintaining
the maximising assumption of a complete lack of galaxies inside increases these
numbers only moderately. Specifically, the amplitude of the spurious
acceleration rises to about 60 km/s, the misalignment angle remains still
smaller than 1 degree, and the fractional change in the deduced value of
Omega_m is enhanced to about 7%. Thus, despite the overall importance of the
Local Void for the motion of the Local Group, the influence of the intersection
of the LV with the ZoA on measurements of the clustering dipole is found to be
only a minor systematic effect.
