Speaker
Prof.
Juan Garcia-Bellido
(IFT, Autonoma de Madrid)
Description
Twenty-three years ago, we predicted that massive primordial
black holes (PBH) would form via the gravitational collapse
of radiation and matter associated with high peaks in the
spectrum of curvature fluctuations, and that they could
constitute all of the dark matter (DM) today. In 2015, we
predicted the clustering and broad mass distribution of PBH,
which peaks at several Msun, and whose high-mass tails could
be responsible for the seeds of all galaxies. Since then,
AdvLIGO-Virgo interferometers have detected gravitational
waves from at least thirty merger events of very massive and
spinless black hole binaries, and we propose that they are
PBH. We have recently understood that a universal mechanism
associated with rapid changes in the number of relativistic
species in the early universe could have been responsible
for the formation of PBH at specific scales and thus have a
very concrete prediction for the mass spectrum of DM-PBH,
with broad peaks at 10^{-5}, 1, 100, and 10^6 Msun. In
particular, the QCD quark-hadron transition could be
responsible for the efficient production of baryons over
antibaryons at PBH collapse, thus explaining the presence of
baryons today and the relative abundance of DM. We predict
that within a few months a less than one solar mass PBH will
be detected by AdvLIGO-Virgo, and that in a few years an
array of GW detectors could be used to determine the mass
and spin distribution of PBH dark matter with 10% accuracy.
Thus, gravitational wave astronomy could be responsible for
a new paradigm shift in the understanding of the nature of
dark matter and galaxy formation.
