Possible Signature of Low Scale Gravity in Ultra High Enegry Cosmic Rays
  We show that the existence of low scale gravity at TeV scale could lead to a direct production of photons with energies above 10^22 eV due to annihilation of ultra high energy neutrinos on relic massive neutrinos of the galactic halo. Air showers initialized in the terrestrial atmosphere by these ultra energetic photons could be collected in near future by the new generation of cosmic ray experiments. 
R.V.Konoplich, S.G.Rubin