Simulating Weak Lensing by Clusters and Large-scale Structure

Selected results on estimating cosmological parameters from simulated weak lensing data with noise are presented. Numerical simulations of ray tracing through N-body simulations have been used to generate shear and convergence maps due to lensing by large-scale structure. Noise due to the intrinsic ellipticities of a finite number of galaxies is added. In this contribution we present our main results on estimation of the power spectrum and density parameter Ω from weak lensing data on several degree sized fields. We also show that there are striking morphological differences in the weak lensing maps of clusters of galaxies formed in models with different values of Ω.