Signals from the Early Universe: Black Holes, Gravitational Waves and Particle Physics

Understand

We dedicate this thesis to the study of signatures coming from the primordial epochs of the universe.

• We will focus in particular on Primordial Black Holes (PBHs), which may be formed from perturbations generated during inflation and might comprise a fraction of the dark matter in the universe.
• In the first part of the thesis, we will address the PBH properties at the time of formation, that are their masses, spins and abundance, and investigate the generation of Gravitational Wave (GW) signals during their production.
• In the second part, we will describe the PBHs evolution across the cosmic history due to their assemble in binaries, phases of baryonic mass accretion and clustering effects.