Drift by coupling to an anti-integrable limit

A symplectic twist map near an anti-integrable limit has an invariant set t hat is conjugate to a full shift on a set of symbols. We couple such a syst em to another twist map in such a way that the resulting system is symplect ic. At the anti-integrable limit we construct a set of nonzero measure of o rbits of the second map that drifts arbitrarily far, even when the coupling is arbitrarily small. Moreover, these drifting orbits persist near the ant i-integrable limit. (C) 2001 Published by Elsevier Science B.V.