Primordial Black Holes as Dark Matter

Primordial black holes are black holes that may have formed  
in the early Universe. Their masses potentially span a range from as  
low as the Planck mass up to many orders of magnitude above the solar  
mass. This, in particular, includes black holes with mass (and spin)  
comparable to those recently discovered by LIGO/Virgo. These may well  
be primordial in nature, which may also be true for those in the  
planetary-mass range as well as those providing the seeds for the  
super-massive black holes in galactic centres. I will discuss a  
natural model which can account for all of these. After a general  
introduction on primordial black holes, I will discuss the most  
consequential aspects of their formation, including recent findings on  
their statistical properties, elaborate on their observable imprints  
as well as on abundance constraints.