  We study numerically the finite temperature and frequency mobility of a
particle coupled by a local interaction to a system of spinless fermions in one
dimension. We find that when the model is integrable (particle mass equal to
the mass of fermions) the static mobility diverges. Further, an enhanced
mobility is observed over a finite parameter range away from the integrable
point. We present a novel analysis of the finite temperature static mobility
based on a random matrix theory description of the many-body Hamiltonian.
