Superluminal noncommutative photons

With the help of the Seiberg-Witten map, one can obtain an effective action of a deformed QED from a noncommutative QED. Starting from the deformed QE D, we investigate the propagation of photons in the back-ground of electrom agnetic field, up to the leading order of the noncommutativity parameter. I n our setting (both the electric and magnetic fields are parallel to the co ordinate axis x(1) and the nonvanishing component of the noncommutativity p arameter is theta (23)), we find that the electric field has no effect on t he propagation of photons, but the velocity of photons can be larger than t he speed of light (c = 1) when the propagating direction of photons is perp endicular to the direction of background magnetic field, while the light-co ne condition does not change when the propagating direction is parallel to the background magnetic field. The causality associated with the superlumin al photons is discussed briefly. (C) 2001 Elsevier Science B.V. All rights reserved.