Disentangling non-Gaussianity, bias and GR effects in the galaxy distribution

Understand

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.