The Abraham–Minkowski controversy is a physics debate concerning electromagnetic momentum within dielectric media.^[1][2] Two equations were first suggested by Hermann Minkowski (1908)^[3] and Max Abraham (1909)^[4][5] for this momentum. They predict different values, from which the name of the controversy derives.^[6] Experimental support has been claimed for both.^{[7][8][9][10]}

The two points of view have different physical interpretations and thus neither need be more correct than the other.^[11] David J. Griffiths argues that, in the presence of matter, only the total stress–energy tensor carries unambiguous physical significance; how one apportions it between an "electromagnetic" part and a "matter" part depends on context and convenience.^[12]

Several papers have claimed to have resolved this controversy.^{[13][14][15][16][17][18]}

The controversy is still of importance in physics beyond the Standard Model where electrodynamics gets modifications, like in the presence of axions.^[19]