Massimiliano Berti, Philippe Bolle
Fast Arnold Diffusion in systems with three time scales
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ABSTRACT.  We consider the problem of Arnold Diffusion for 
nearly integrable partially isochronous Hamiltonian 
systems with three time scales.  
By means of a careful shadowing analysis, based on a variational technique,
we prove that, along special directions, Arnold diffusion 
takes place with fast (polynomial) speed, even though the ``splitting 
determinant'' is exponentially small.