Constraints on power spectrum of density fluctuations from PBH   evaporations
  We calculate neutrino and photon energy spectra in extragalactic space from evaporation of primordial black holes, assuming that the power spectrum of primordial density fluctuations has a strong bump in the region of small scales. The constraints on the parameters of this bump based on neutrino and photon cosmic background data are obtained. 
Edgar Bugaev, Peter Klimai