  The MareNostrum Universe is one of the biggest SPH cosmological simulations
done so far. It contains more than 2 billion particles (2 times 1024^3) in a
500 Mpc/h cubic volume. This simulation has been performed on the MareNostrum
supercomputer at the Barcelona Supercomputer Center. We have obtained more than
0.5 million halos with masses greater than a typical Milky Way galaxy halo. We
report results about the halo mass function, the shapes of dark matter and gas
distributions in halos, the baryonic fraction in galaxy clusters and groups,
baryon oscillations in the dark matter and the halo power spectra as well as
the distribution and evolution of the gas fraction at large scales.
