Constraints on primordial non-Gaussianity using multitracer technique
  for skew spectrum
  Extracting the bispectrum information from the large scale structure
observations is challenging due to the complex models and the computational
costs to measure the signal and its covariance. Recently, the skew spectrum was
proposed to access parts of the bispectrum information with a more effective
way and has been confirmed it can provide complementary information to that
enclosed in the power spectrum measurements. In this work, we generalize the
theory to apply the multitracer technique and explore its ability to constrain
the local type primordial non-Gaussianity. Using the spectra and their
covariance estimated from $N$-body simulations, we find the multitracer
approach is effective to reduce the cosmic variance noise. The $1\sigma$
marginalized errors for $b_1^2A_s, n_s$ and $f_{\rm NL}^{\rm loc}$ are reduced
by 50\%, 52\% and 73\% comparing with the results using only power spectrum
obtained from a single tracer. It indicate that both the skew spectrum and the
multitracer technique are useful to constrain the primordial non-Gaussianity
with the forthcoming wide-field galaxy surveys.
