  In this paper I review the main topics on the energetic Universe that have
been put forward as main science goals in the Cosmic Vision 2015-2025 exercise.
I discuss the study of matter under extreme conditions (both under strong
gravity and at ultra-high densities), the cosmology of baryons (assembly of
ordinary matter in dark-matter dominated structures and the creation of heavy
elements) and the co-eval growth of super-massive black holes and stars in
galaxies along cosmic history. Most of these topics can be addressed with a
large-aperture deep Universe X-ray space observatory that can be flown soon
after 2015, complemented by gravitational wave observatories (LISA), a
focussing gamma-ray observatory, a far infrared high-sensitivity observatory
and an X-ray survey telescope.
