“…Thus, it differs conceptually from the classical plane wave and may serve as a regularization of the latter. In the same sense it differs from the q-plane wave in the paper [11], which is not surprising, since there is used different q-Minkowski space-time (from [2,3,4] and different q-d'Alembert equation both based only on a (different) q-Lorentz algebra, and not on qconformal (or U q (sl(4))) symmetry as in our case. In fact, it is not clear whether the q-Lorentz algebra of [2,3,4] used in [11] is extendable to a q-conformal algebra.…”