Cosmology seminar: Ilia Musco: Causal horizons and structure formation in the early Universe

 I present first a discussion of causal horizons, both for
black holes and for the universe, emphasizing the similarities between
the two situations. The discussion uses spherical symmetry but does not
assume that the black holes are stationary or surrounded by vacuum, or
that the universe is homogeneous. I then discuss issues concerned with
initial conditions and simulation of cosmological structure formation in
the early universe. If in spherical symmetry we choose a barotropic
equation of state, only primordial black holes can be formed, and recent
simulations showing this are presented. Instead if we consider a non
barotropic equation of state it looks possible to obtain also in
spherical symmetry the process of virialization, necessary for the
formation of non relativistic structures as we observe in the present
universe.