Phase-Space Delaunay Tessellation Field Estimator

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 tracks the dark matter fluid in phase-space. The new reconstruction scheme removes several artifacts from the conventional DTFE in multi-stream regions, while preserving the adaptive resolution in high-density regions and yielding continuous fields. The estimator also removes tessellation artifacts of a previously proposed phase-space reconstruction scheme.