Noncommutativity in Field Space and Lorentz Invariance Violation

Abstract

The connection between Lorentz invariance violation and noncommutativity of fields in a quantum field theory is investigated. A new dispersion relation for a free field theory with just one additional noncommutative parameter is obtained. While values for the noncommutative scale much larger than 10^{-20} eV^{-1} are ruled out by the present experimental status, cosmic ray physics would be compatible with and sensible to a noncommutativity arising from quantum gravity effects. We explore the matter-antimatter asymmetry which is naturally present in this framework.

Comments: 10 pages, no figures. Final version to appear in Phys. Lett. B with slight changes in the presentation