Bounds on warm dark matter from Schwarzschild primordial black holes
  We consider light dark matter candidates originated from the evaporation of
Schwarzschild primordial black holes, with masses in the range $10^{-5}-10^9$
g. These candidates are beyond Standard Model particles with negligible
couplings to the other particles, so that they interact only gravitationally.
Belonging to the category of warm dark matter, they nevertheless spoil
structure formation, with a softer impact for increasing values of the
candidate spin. Requiring such candidates to fully account for the observed
dark matter, we find that the scenario of black hole domination is ruled out
for all spin values up to 2. For the scenario of radiation domination, we
derive upper limits on the parameter $\beta$ (the primordial black hole energy
density at formation over the radiation one), which are less stringent the
higher the candidate spin is.
