PowerI4 is an estimator of the Fourier-space density and power spectrum of particle distributions in a simulation box for cosmological applications and the analysis of N-body results. It implements an interlacing technique and 4th-order interpolation that allow a reduction of aliasing spurious contributions below the percent level for all wavenumbers up to the Nyquist frequency.

{"references": ["Sefusatti, Crocce, Scoccimarro & Couchman, MNRAS 460, 3624 (2016)."]}