Phase-space Delaunay tessellation field estimator

ABSTRACT The reconstruction of density and velocity fields is of central importance to the interpretation of N-body simulations. We propose a phase-space extension of the Delaunay tessellation field estimator (DTFE) that uses the mapping from Lagrangian to Eulerian space to track the dark matter fluid in phase-space. The new reconstruction scheme removes several artefacts from the conventional DTFE in multistream regions, while preserving the adaptive resolution in high-density regions and yielding continuous fields. The estimator also removes some tessellation artifacts of a previously proposed phase-space reconstruction scheme. The method is particularly suitable to the estimation of density and velocity fields of N-body simulations with multiple particle species and/or starting with glass initial conditions.