## The universe in a supercomputer: From the first quasars to the large-scale galaxy distribution

#### Volker SpringelMax Planck Institute for Astrophysics

I present first results from the Millennium Simulation', the largest cosmological N-body calculation performed to date. Using an unprecedented 10^10 particles to represent cold dark matter, we track structure growth with a spatial resolution of 16 thousand light-years within a typical region of the Universe more than 2 billion light-years across. Approximately 20 million dark matter halos form in this region and we follow post hoc the formation of visible galaxies within them, using simple physical models for the cooling and condensation of gas, for its transformation into stars, for the growth of supermassive black holes in galaxy cores, and for the associated energetic feedback processes. We construct complete catalogs of galaxies brighter than 10%
of the characteristic luminosity in a volume comparable to those probed by the new generation of large galaxy surveys, the 2-degree field' galaxy redshift survey (2dFGRS) and the SDSS. Our model galaxies reproduce the small-scale clustering seen in the 2dFGRS remarkably well. On large scales we demonstrate that `baryon wiggles', corresponding to the acoustic peaks in the cosmic microwave background radiation, are present in the galaxy clustering pattern, raising the exciting possibility that the evolution of cosmic dark energy may be measured by the next generation of galaxy surveys.

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