Effect of primordial non-Gaussianity on halo bias and mass function.

We discuss the effect of quadratic and cubic local non-Gaussianity on the mass function and bias of dark matter halos extracted from cosmological N-body simulations. This type of non-Gaussianity induces a k-dependent bias in the large-scale clustering of rare objects. While we find that at low wavenumbers k<0.03 hMpc-1 the theory and the simulations agree well with each other for biased halos with b(M)>1.5, including a scale independent correction to the non-Gaussian bias improves the agreement on small scales where the k-dependent effect becomes rapidly negligible. Using available large-scale structure data, we obtain a limit on the size of the cubic nonlinear parameter of -3.5×105< gNL<8.2×105. Future observations shall improve this bound by 1¿2 orders of magnitud