Steady-state theory of electron drag on polariton condensates

We present a general theory of drag on a condensate due to interactions with a moving thermal bath of non-condensate particles, adapted from previous theory of equilibration of a condensate in a trap. This theory can be used to model the polariton drag effect observed previously, in which an electric current passing through a polariton condensate gives a measurable momentum transfer to the condensate, and an effective potential energy shift.