TITLE: 
Converse KAM Theory for monotone positive symplectomorphisms

AUTHOR:
Alex Haro
Departament de Matematica Aplicada i Analisi
Universitat de Barcelona
Gran Via 585
Barcelona (SPAIN)

ABSTRACT:
We apply variational methods to Converse KAM theory. These are useful
for symplectomorphisms in the annulus that satisfy
weaker hypotheses than those usually required. For instance, we do not need
the existence of a global Lagrangian generating function.
We obtain the variational principles from the primitive function of our
symplectomorphism.
They are introduced not only for the orbits of a
symplectomorphism, but also for the so-called invariant Lagrangian graphs.
Among the non-degenerate i.L.g. we focus on the minimizing ones.
Applications are also described for a broad class of examples.