Hans Koch
On the Renormalization of Hamiltonian Flows, and Critical Invariant Tori
(54K, plain TeX)
ABSTRACT. We analyze a renormalization group transformation R for
partially analytic Hamiltonians, with emphasis on what seems to be
needed for the construction of non-integrable fixed points. Under
certain assumptions, which are supported by numerical data in the
golden mean case, we prove that such a fixed point has a critical
invariant torus. The proof is constructive and can be used for
numerical computations. We also relate R to a renormalization group
transformation for commuting maps.