Condensation kinetics for bosonic excitons interacting with a thermal phonon bath

We develop a theory of the kinetics of the Bose-Einstein condensation of bosonic excitons interacting with a thermal bath of acoustic phonons. We emphasize several delicate aspects of the condensation kinetics within the framework of rate equations. We give detailed proofs about the existence and uniqueness of the solution with a condensate and illustrate details within exactly or almost exactly solvable models. In particular, we predict an exciton condensation time in Cu2O which is shorter than the lifetime of paraexcitons.