Lorentz symmetry of the noncommutative chiral bosons

We study issues of Lorentz violation symmetry in the context of the recently proposed theory of noncommutative fields [J. Carmona, J. L. Cortes, J. Gamboa, and F. Mendes, J. High Energy Phys. 03 (2003) 058; Phys. Lett. B 565, 222 (2003).], using the soldering formalism. To this end a noncommutative chiral boson with a deformed algebra [A. Das, J. Gamboa, F. Mendes, and J. Lopes-Sarrion, J. High Energy Phys. 05 (2004) 022.], used to study these notions in D = 2, is properly generalized. We verify, also for this larger group of theories that, although the structure of the Lorentz group is preserved, the velocity of light is scaled by a function of the deformation parameter, as recently claimed., However, we found a subset of models where the velocity of propagation is maintained in spite of the presence of the deformed algebra. Effects of a preferred frame of reference manifest by the presence of birefringence were also studied in the chiral boson framework leading to the scalar sector of the extended standard model recently proposed.