Abstract

Although today’s best observational constraints on primordial non-Gaussianity come from the CMB , recent developments indicate that galaxy surveys can yield comparable or even better constraints in the near future. To achieve this we need to understand how primordial non-Gaussianity affects the formation of large scale structures, in particular how it changes the power spectrum, bispectrum and higher horder correlation functions of the dark matter and galaxy distribution. We present novel methods to generate general non-Gaussian initial conditions for N-body simulations and estimate the bispectrum in a model-independent manner. The methods are based on a separable decomposition of the bispectrum, which has been applied successfully to CMB bispectrum analyses, and are significantly faster than previously used techniques, allowing us to examine a wider range of scales. We show how this can be used to disentangle the primordial contribution to the matter bispectrum from the late-time non-Gaussianity induced by non-linear gravitational evolution.