Non-Gaussianity Constraints using Future Radio Continuum Surveys and the
  Multi-Tracer Technique
  Tighter constraints on measurements of primordial non-Gaussianity will allow
the differentiation of inflationary scenarios. The cosmic microwave background
bispectrum-the standard method of measuring the local non-Gaussianity-is
limited by cosmic variance. Therefore, it is sensible to investigate
measurements of non-Gaussianity using the large-scale structure. This can be
done by investigating the effects of non-Gaussianity on the power spectrum on
large scales. In this study we forecast the constraints on the local primordial
non-Gaussianity parameter $f_{\rm NL}$ that can be obtained with future radio
surveys. We utilize the multi-tracer method which reduces the effect of cosmic
variance and takes advantage of the multiple radio galaxy populations which are
differently biased tracers of the same underlying dark matter distribution.
Improvements on previous work include the use of observational bias and halo
mass estimates, updated simulations and realistic photometric redshift
expectations, thus producing more realistic forecasts. Combinations of SKA
simulations and radio observations were used as well as different redshift
ranges and redshift bin sizes. It was found that in the most realistic case the
1 - $\sigma$ error on $f_{\rm NL}$ falls within the range 4.07 and 6.58,
rivalling the tightest constraints currently available.
