Gravitational Wave Anisotropies from Primordial Black Holes
  An observable stochastic background of gravitational waves is generated
whenever primordial black holes are created in the early universe thanks to a
small-scale enhancement of the curvature perturbation. We calculate the
anisotropies and non-Gaussianity of such stochastic gravitational waves
background which receive two contributions, the first at formation time and the
second due to propagation effects. The former contribution can be generated if
the distribution of the curvature perturbation is characterized by a local and
scale-invariant shape of non-Gaussianity. Under such an assumption, we conclude
that a sizeable magnitude of anisotropy and non-Gaussianity in the
gravitational waves would suggest that primordial black holes may not comply
the totality of the dark matter.
