Gravitational couplings of charged leptons in a medium - art. no. 085004

We calculate the leading order matter-induced corrections to the gravitatio nal interactions of charged leptons and their antiparticles in a medium tha t contains electrons but not the other charged leptons, such as normal matt er. The gravitational coupling, which is universal at the tree level, is fo und to be flavor dependent, and also different for the corresponding antipa rticles, when the corrections of O(alpha) are taken into account. General e xpressions are obtained for the matter-induced corrections to the gravitati onal mass in a generic matter background, and explicit formulas for those c orrections are given in terms of the macroscopic parameters of the medium f or particular conditions of the background gases.