A high-fidelity realization of the Euclid code comparison N-body simulation with Abacus. Issue 3 (7th March 2019) - Garrison, Lehman H
Abstract: We present a high-fidelity realization of the cosmological N -body simulation from the Schneider et al. code comparison project. The simulation was performed with ourAbacus N -body code, which offers high-force accuracy, high performance, and minimal particle integration errors. The simulation consists of 2048 3 particles in a$500\ h^{-1}\, \mathrm{Mpc}$ box for a particle mass of$1.2\times 10^9\ h^{-1}\, \mathrm{M}_\odot$ with$10\ h^{-1}\, \mathrm{kpc}$ spline softening.Abacus executed 1052 global time-steps to z = 0 in 107 h on one dual-Xeon, dual-GPU node, for a mean rate of 23 million particles per second per step. We findAbacus is in good agreement withRamses andPkdgrav3 and less so withGadget3 . We validate our choice of time-step by halving the step size and find sub-percent differences in the power spectrum and 2PCF at nearly all measured scales, with${\lt }0.3{{\ \rm per\ cent}}$ errors at$k\lt 10\ \mathrm{Mpc}^{-1}\, h$ . On large scales, Abacus reproduces linear theory better than 0.01 per cent. Simulation snapshots are available athttp://nbody.rc.fas.harvard.edu/public/S2016 .