A fast particle-mesh simulation of non-linear cosmological structure formation with massive neutrinos

Understand

Quasi-N-body simulations, such as FastPM, provide a fast way to simulate cosmological structure formation, but have yet to adequately include the effects of massive neutrinos.

• We present a method to include neutrino particles in FastPM, enabling computation of the CDM and total matter power spectra to percent-level accuracy in the non-linear regime.
• The CDM-neutrino cross-power can also be computed at a sufficient accuracy to constrain cosmological observables.
• To avoid the shot noise that typically plagues neutrino particle simulations, we employ a quasi-random algorithm to sample the relevant Fermi-Dirac distribution when setting the initial neutrino thermal velocities.