Constraints on the ultracompact minihalos using neutrino signals from
  the gravitino dark matter decay
  Ultracompact dark matter minihalos (UCMHs) would be formed during the earlier
universe if there were large density perturbations. If the dark matter can
decay into the standard model particles, such as neutrinos, these objects would
become the potential astrophysical sources and could be detected by the related
instruments, such as IceCube. In this paper, we investigate the neutrino
signals from the nearby UCMHs due to the gravitino dark matter decay and
compare these signals with the background neutrino flux which is mainly from
the atmosphere to get the constraints on the abundance of UCMHs.
