Probing primordial non-Gaussianity with large-scale structure

We consider primordial non-Gaussianity due to quadratic corrections in the gravitational potential parametrized by a nonlinear coupling parameter [Formula Presented] We study constraints on [Formula Presented] from measurements of the galaxy bispectrum in redshift surveys. Using estimates for idealized survey geometries of the 2dF and SDSS surveys and realistic ones from SDSS mock catalogs, we show that it is possible to probe [Formula Presented] after marginalization over bias parameters. We apply our methods to the galaxy bispectrum measured from the PSCz survey, and obtain a [Formula Presented] constraint [Formula Presented] We estimate that an all sky redshift survey up to [Formula Presented] can probe [Formula Presented] We also consider the use of cluster abundance to constrain [Formula Presented] and find that in order to be sensitive to [Formula Presented] cluster masses need to be determined with an accuracy of a few percent, assuming perfect knowledge of the mass function and cosmological parameters.