Noise-activated escape from a sloshing potential well

We treat the noise-activated escape from a one-dimensional potential well o f an overdamped particle, to which a periodic force of fixed frequency is a pplied. Near the well top, the relevant length scales and the boundary laye r structure are determined. We show how behavior near the well top generali zes the behavior determined by Kramers. in the case without forcing. Our an alysis includes the case when the forcing does not die away in the weak-noi se limit. We discuss the relevance of scaling regimes, defined by the relat ive strengths of the forcing and the noise, to recent optical trap experime nts.