  According to the Smoluchowski-Kramers approximation, the solution of the
equation
${\mu}\ddot{q}^{\mu}_t=b(q^{\mu}_t)-\dot{q}^{\mu}_t+{\Sigma}(q^{\mu}_t)\dot{W}_t,
q^{\mu}_0=q, \dot{q}^{\mu}_0=p$ converges to the solution of the equation
$\dot{q}_t=b(q_t)+{\Sigma}(q_t)\dot{W}_t, q_0=q$ as {\mu}->0. We consider here
a similar result for the Langevin process with elastic reflection on the
boundary.
