Disentangling non-Gaussianity, bias and GR effects in the galaxy
  distribution
  Local non-Gaussianity, parametrized by $f_{\rm NL}$, introduces a
scale-dependent bias that is strongest at large scales, precisely where General
Relativistic (GR) effects also become significant. With future data, it should
be possible to constrain $f_{\rm NL} = {\cal O}(1)$ with high redshift surveys.
GR corrections to the power spectrum and ambiguities in the gauge used to
define bias introduce effects similar to $f_{\rm NL}= {\cal O}(1)$, so it is
essential to disentangle these effects. For the first time in studies of
primordial non-Gaussianity, we include the consistent GR calculation of galaxy
power spectra, highlighting the importance of a proper definition of bias. We
present observable power spectra with and without GR corrections, showing that
an incorrect definition of bias can mimic non-Gaussianity. However, these
effects can be distinguished by their different redshift and scale dependence,
so as to extract the true primordial non-Gaussianity.
