Cosmic neutrinos and new physics beyond the electroweak scale - art. no. 055001

New physics beyond the electroweak scale may increase weak interaction cros s sections beyond the standard model predictions. Such cross sections can b e expected within theories that solve the hierarchy problem of known intera ctions with a unification scale in the TeV range. We derive constraints on these cross sections from the Hus of neutrinos expected from cosmic ray int eractions with the microwave background and the non-observation of horizont al air showers. We also discuss how this limit can be improved by upcoming cosmic ray ansi neutrino experiments, and how the energy dependence of the new interactions can be probed by these experiments.