A note on the geometrical-optics solution to the Maxwell tensor wave equation in curved spacetime

We examine and solve a problem of physical consistency posed by a published geometrical-optics solution to the Maxwell tensor wave equation in curved spacetime. We show that the claim about the non-null and nongeodesic character of the solution is ill-founded, and cannot therefore be employed to confute the possibility of superluminal propagation arising from nonminimally coupled Lagrangians. (C) 2010 Elsevier B.V. All rights reserved.