Code Comparison Project

Upcoming galaxy surveys require percent precision in the theoretical knowledge of the matter power spectrum. While this level of accuracy is easily obtained in the linear regime with perturbation theory, it represents a serious challenge for small scales where numerical simulations are required.

In the framework of the Cosmological Simulation Working Group of the Euclid Consortium, we are carrying out a rigorous comparison project of numerical simulations and subsequent analysis tools. The N-body code comparison currently includes Ramses, Pkdgrav, and Gadget which represent three main discretisation techniques: the particle-mesh method, the tree method, and a hybrid combination of the two (more information can be found in Schneider et al 2016).

Here, we provide relevant data of the comparison project (i.e. IC-files, power spectrum measurements, run-parameters). By doing so, we want to enable other groups to compare their N-body code to our findings.

Reference Run (L=500 Mpc/h box with N=2048 particles per dimension):

  Cosmological parameters (Planck 2013):

  IC-file (standard gadget format):

  Power spectrum measurements (without shot-noise correction):