Primordial black holes are again on the limelight
  We derive a strong upper bound on the amount of Primordial Black Holes (PBHs)
that can still be present in the Universe. Gravitational capture of PBHs by the
Milky Way stars during their formation and subsequent accretion would produce a
dramatic depletion of disk stars and especially of white dwarfs, unless the
average cosmic density and mass of PBHs are severely constrained. Our finding
also helps to discriminate among the various production mechanisms of PBHs.
Moreover, we show that a star becomes overluminous before its disappearance
into a PBH for a time span independent of its mass, thereby providing a
characteristic observational signature of the considered scenario. We stress
that our result allows for the existence of stellar-mass black holes in a mass
range that is forbidden by standard stellar evolution.
