Energy, linear momentum and mass transfer by an electromagnetic wave in a negative-refraction medium

The problem of photon linear momentum in a refracting medium is discussed. It is shown that the relations P = hplankak and ΔM = E/c2 cannot hold simultaneously in a refracting medium and that in the particular case of a negative-refraction medium, light pressure is replaced by light attraction. It is also shown that the Abraham energy-momentum tensor is actually not a tensor because of its lack of relativistic invariance. (methodological notes)