Photon-neutrino interaction in θ-exact covariant noncommutative field theory

Photon-neutrino interactions arise quite naturally in noncommutative field theories. Such couplings are absent in ordinary field theory and imply experimental lower bounds on the energy scale ΛNC∼|θ|-2 of noncommutativity. Using nonperturbative methods and a Seiberg-Witten map based covariant approach to noncommutative gauge theory, we obtain θ-exact expressions for the interactions, thereby eliminating previous restrictions to low-energy phenomena. We discuss implications for plasmon decay, neutrino charge radii, big bang nucleosynthesis, and ultrahigh energy cosmic rays. Our results behave reasonably throughout all interaction energy scales, thus facilitating further phenomenological applications.