Ultra-high energy neutrino-nucleon interactions

Ultra-high energy ($E_{\nu }>{10}^8$ GeV) neutrino-nucleon total cross sections ${\sigma }^{\nu N}$ are estimated from a soft non-perturbative model complemented by an approximate QCD evolution, explicitly calculated. The resulting asymptotic energy behavior of the neutrino-nucleon charged-current total cross section is derived analytically and predictions concerning the observation of ultra-high energy neutrinos in future experiments are presented.