  Current-driven vibrational non-equilibrium induces vibrational sidebands in
single-molecule transistors which arise from tunneling processes accompanied by
absorption of vibrational quanta. Unlike conventional sidebands, these
absorption sidebands occur in a regime where the current is nominally Coulomb
blockaded. Here, we develop a detailed and analytical theory of absorption
sidebands, including current-voltage characteristics as well as shot noise. We
discuss the relation of our predictions to recent experiments.
