  In light of the mounting evidence that the highest energy cosmic rays are
dominated by protons and not gamma-rays, we discuss the prospect that these
cosmic rays are generated in the decay or annihilation of superheavy relic
particles. We calculate the high energy neutrino spectrum which results and
normalize our results to the ultra-high energy cosmic ray spectrum. We show
that most scenerios are already constrained by present limits placed by the
AMANDA experiment.

High Energy Physics - Phenomenology;Astrophysics