Demonstrating Discreteness and Collision Error in Cosmological N-body Simulations of Dark Matter Gravitational Clustering

Two-body scattering and other discreteness effects are unimportant in cosmological gravitational clustering in most scenarios, since the dark matter has a small particle mass. The collective field should determine evolution: Two–body scattering in simulations violates the Poisson–Vlasov equations. We test this in PM, PM, Tree, and NGPM codes, noting that a… (More)