Multiple tracers of the same surveyed volume can enhance the signal-to-noise on a measurement of local primordial non-Gaussianity and the relativistic projections. Increasing the number of tracers comparably increases the number of shot noise terms required to describe the stochasticity of the data. Although the shot noise is white on large scales, it is desirable to investigate the extent to which it can degrade constraints on the parameters of interest.
We calcuate the effect of marginalization over shot noise on statistical errors and the effect of assumtion of a wrong model for the shot noise on systematic errors of local primordial non-Gaussianity and the relativistic projections parameters.
We show that the optimal division of the halos into mass bins in order to minimise statistical errors for the local primordial non-Gaussianity and the relativistic projections parameters . We also emphasize that the non-Poissonian noise corrections that arise from small-scale clustering effects cannot be measured with random dilutions of the data. Therefore, they must either be properly modeled or marginalized over.