G. Gallavotti
Hamilton--Jacobi's equation and Arnold's diffusion
near invariant tori in a priori unstable isochronous 
systems.
(44K, TeX (as plain as it can be))

ABSTRACT.  Local integrability of hyperbolic oscillators
is discussed to provide an introductory example of the Arnold's
diffusion phenomenon in a forced pendulum. This is a text prepared 
for the ISI summer school of June 1997 and deals 
with developments of the topics treated in the lectures.