DEUS – FULL UNIVERSE RUN
Our team, including J.-M. Alimi, Y. Rasera, P.-S. Corasaniti, V. Bouillot, V. Reverdy and I. Balmes, has performed the first numerical N-body simulation of the full observable Universe. At the present time this is the largest and most performing dark matter simulation of the entire cosmos ever realized, probing scales from 40 kpc/h to 21 Gpc/h for the concordance ΛCDM model. We are especially grateful to the teams from GENCI (www.genci.fr) and TGCC (www-hpc.cea.fr/fr/complexe/tgcc-curie.htm) for their support.
This immense simulation has evolved 550 billion of particles from an initial redshift of z=100 down to z=0. About 1.5 Po of data have been produced, which consists in numerous snapshots (31), light-cones and sub-samples (at each coarse time step). This simulation has been run on 76032 cores of the BULL supercomputer Curie Thin at TGCC center.
The evolution of dark matter particles is computed using a Particle-Mesh (PM) solver within an Adaptive Mesh Refinement (AMR) grid, while the Poisson equation is solved with a multi-grid method. Using a density based refinement criterion, the code dynamically zoom-in and follows all the overdense regions within the cosmological volume. We have developed a new version, RAMSES_DEUS, of the cosmological code RAMSES (Teyssier, 2002) in which memory occupancy (special thanks to P. Wautelet at IDRIS), MPI communications and the control of I/O have been deeply improved. We have also coupled our new dynamical code with a complete chain of post-processing programs.
We are very thankful to Romain Teyssier (RAMSES code), Simon Prunet & Christophe Pichon (MPGRAFIC), Fabrice Roy (PFOF) for providing their original applications and for their valuable advices that allowed us to optimize and develop the codes used for the realization of this project.
Hereafter we present some preliminary results. Publications concerning the complete results from DEUS and DEUS Full Universe Run projects will be posted shortly.