Efficient electroweak baryogenesis by black holes
  A novel cosmological scenario, capable to generate the observed baryon number
at the electroweak scale for very small CP violating angles, is presented. The
proposed mechanism can be applied in conventional FRW cosmology, but becomes
extremely efficient due to accretion in the context of early cosmic expansion
with high energy modifications. Assuming that our universe is a Randall-Sundrum
brane, baryon asymmetry can easily be produced by Hawking radiation of very
small primordial black holes. The Hawking radiation reheats a spherical region
around every black hole to a high temperature and the electroweak symmetry is
restored there. A domain wall is formed separating the region with the
symmetric vacuum from the asymmetric region where electroweak baryogenesis
takes place. First order phase transition is not needed. The black holes's
lifetime is prolonged due to accretion, resulting to strong efficiency of the
baryon producing mechanism. The allowed by the mechanism black hole mass range
includes masses that are energetically favoured to be produced from
interactions around the higher dimensional Planck scale.
