Probing dark matter signals in neutrino telescopes through angular power
  spectrum
  The hypothesis of two different components in the high-energy neutrino flux
observed with IceCube has been proposed to solve the tension among different
data-sets and to account for an excess of neutrino events at 100 TeV. In
addition to a standard astrophysical power-law component, the second component
might be explained by a different class of astrophysical sources, or more
intriguingly, might originate from decaying or annihilating dark matter. These
two scenarios can be distinguished thanks to the different expected angular
distributions of neutrino events. Neutrino signals from dark matter are indeed
expected to have some correlation with the extended galactic dark matter halo.
In this paper, we perform angular power spectrum analyses of simulated neutrino
sky maps to investigate the two-component hypothesis with a contribution from
dark matter. We provide current constraints and expected sensitivity to dark
matter parameters for future neutrino telescopes such as IceCube-Gen2 and
KM3NeT. The latter is found to be more sensitive than IceCube-Gen2 to look for
a dark matter signal at low energies towards the galactic center. Finally, we
show that after 10 years of data-taking, they will firmly probe the current
best-fit scenario for decaying dark matter by exploiting the angular
information only.
