Chaos and noise in a truncated Toda potential.

Results are reported from a numerical investigation of orbits in a truncated Toda potential which is perturbed by weak friction and noise. Two signiicant conclusions are shown to emerge: (1) Despite other nontrivial behaviour, connguration, velocity, and energy space moments associated with these perturbations exhibit a simple scaling in the amplitude of the friction and noise. (2) Even very weak friction and noise can induce an extrinsic diiusion through cantori on a time scale much shorter than that associated with intrinsic diiusion in the unperturbed system.