Primordial Black Holes: from Theory to Gravitational Wave Observations
  Primordial Black Holes (PBH) can form in the early universe and might
comprise a significant fraction of the dark matter. Interestingly, they are
accompanied by the generation of Gravitational Wave (GW) signals and they could
contribute to the merger events currently observed by the LIGO/Virgo
Collaboration (LVC). In this thesis, we study the PBH scenario, addressing
various properties at the formation epoch and the computation of abundance
beyond the Gaussian paradigm, while also developing the theoretical description
of PBH evolution through accretion and mergers, with particular focus on
modelling their GW signatures. In a second part, we compare the primordial
scenario with current GW data, seizing the possible contribution of PBH
binaries to LVC signals and forecasting the potential of future GW detectors,
such as Einstein Telescope and LISA, to detect mergers of primordial binaries
and the stochastic GW background induced at second order by the PBH formation
mechanism.
